AP 9th Class Physical Science 1st Lesson Important Questions Matter in Our Surroundings

These AP 9th Class Physics Important Questions 1st Lesson Matter in Our Surroundings will help students prepare well for the exams.

AP 9th Class Physical Science 1st Lesson Matter in Our Surroundings Important Questions

Class 9 Physical Science Chapter 1 Important Questions – 2 Marks

Question 1.
Observe the table and state the states of substances A, B & C.

Substance	Shape	Volume
A	Not fixed	Not fixed
B	Fixed	Fixed
C	Not fixed	Fixed

Answer:

1. State of substance A is a gaseous state.
2. State of substance B is a solid state.
3. State of substance C is a liquid state.

Question 2.
Have you observed a balloon seller fill a large number of balloons from a single cylinder ? How is it possible ?
Answer:

1. A large amount of gas is compressed and filled in a single cylinder.
2. So, it is sufficient to fill a large number of balloons.
3. From this we can conclude that gas has no fixed volume.

Question 3.
Which of the following situation is possible to do ? Give reasons.
Situation A : 1000 ml of water can be completely transferred in 750 ml container.
Situation B : 1000 ml of LPG can be completely transformed into 750 ml container.
Answer:

1. Situation B can possible to do.
2. Gas can compress and fill in container.
3. But liquid cannot be compressed and its volume is fixed.

Question 4.
In which state kinetic energy of particles is more ? Why ?
Answer:

1. In the gaseous state K.E is more.
2. In the gaseous state, the particles move randomly at high speed because they contain more space to move.

Question 5.
How do you say particles of matter have space between them ?
Answer:
When we make tea, coffee or lemonade (nimbu paani), particles of one type of matter get into the spaces between particles of the other. This shows that there is enough space between particles of matter.

Question 6.
Describe the arrangement of particles in solids, liquids and gases.
Answer:

1. The arrangement of particles is most ordered in the case of solids.
2. In the case of liquids layers of particles can slip and slide over each other.
3. But in the gases, there is no order, particles just move about randomly.

Question 7.
Vani noticed that the water particles were faster while boiling the water. What is the reason ?
Answer:

1. When water molecules absorb heat energy, the kinetic energy of water molecules increases.
2. This increase in K.E. causes the rapid velocity of water particles.

Question 8.
When a solid (ice) melts, its temperature remains the same, so where does the heat energy go ? Explain.
Answer:

1. This heat gets used up in changing the state by overcoming the forces of attraction between the particles.
2. As this heat energy is absorbed by ice without showing any rise in temperature, it is considered that it gets hidden into the contents of the beaker and is known as the latent heat.

Question 9.
What happens when we supply heat energy to the water continuously ?
Answer:

1. When we supply heat energy to water, particles start moving even faster.
2. At a certain temperature, a point is reached when the particles have enough energy to break free from the forces of attraction of each other.
3. At this temperature the liquid starts changing into gas.

Question 10.
Write correct words at ‘a’ and ‘b’ in the given diagram and re-write in your answer book.

Question 11.
a) In which figure pressure is more ?
b) If you take CO₂ in the given cylinder, can we get dry ice ?

Answer:
a) In third cylinder pressure is more.
b) Yes, we can get dry ice by compressing CO₂ gas.

Question 12.
Can you quote some examples from everyday life where change of state from liquid to vapour takes place without the liquid reaching the boiling point ?
Answer:

1. Water, when left uncovered, slowly changes into vapour. Wet clothes dry up.
2. In the given examples, water does not reach the boiling point but state of liquid can change into vapour.

Question 13.
Siddhu observed that clothes dry faster on a windy day. Write the reason.
Answer:

1. It is a common observation that clothes dry faster on a windy day.
2. With the increase in wind speed, the particles of water vapour move away with the wind, decreasing the amount of water vapour in the surrounding.

Question 14.
What is humidity ? How does it affect evaporation ?
Answer:

1. Humidity is the amount of water vapour present in air.
2. The air around us cannot hold more than a definite amount of water vapour at a given temperature. If the amount of water in air is already high, the rate of evaporation decreases.

Question 15.
Petrol is leaked from a tanker. You are away from the tanker, but you can recognize the smell of the petrol. How is it possible ?
Answer:

1. The evaporated petrol particles move through the air and reaches us.
2. It is called a process of diffusion.
3. So, we can recognise the smell of the petrol eventhough we are away frorm the leaked tanker.

Question 16.
Take a vessel with water or any liquid. Keeps on evaporating it. Then what happens to the surroundings ? Do they get cool down or heat up ? Why ?
Answer:

1. When the liquid keeps on evaporating the surroundings cool down.
2. The particles of liquid absorb energy from the surroundings to regain the energy lost during evaporation.
3. This absorption of energy from the surroundings makes the surroundings cold.

Question 17.
How does cotton make us comfort in summer ?
(OR)
Why should we wear cotton clothes in summer ?
Answer:
Cotton, being a good absorber of water helps in absorbing the sweat and exposing it to the atmosphere for easy evaporation.

Question 18.
Why do we see water droplets on the outer surface of a glass containing ice-cold water? (OR)
Take some ice-cold water in a tumbler. Soon we will see water droplets on the outer surface of the tumbler. Why ?
Answer:

1. The water vapour present in air, on coming in contact with the cold glass of water, loses energy and gets converted to liquid state, which we see as water droplets.
2. It is called condensation.

Question 19.
Define melting and boiling point.
Answer:
The temperature at which solid changes to liquid state is known as melting point.
The temperature at which a liquid change to gaseous (Vapour state) is known as boiling point.

Question 20.
Define latent heat of fusion.
Answer:
The amount of heat energy absorbed when a substance changes from solid to liquid at its melting point is called the latent heat of fusion of the solid.

Question 21.
Define latent heat of vaporisation.
Answer:
The amount of heat energy absorbed when a substance changes from liquid to vapour at its boiling point is called the latent heat of vaporisation of the liquid.

Question 22.
Why is the rate of diffusion in gases high ?
Answer:
The rate of diffusion in gases is very high, because

1. the attraction forces between particles are less,
2. the distance between particles is maximum.
   So, particles can move fastly.

Question 23.
Purna Chandra does not recognise the difference between solids and liquids. Prepare some questions, by which he can understand the differences between them.
Answer:

1. What is solid ?
2. Does solids have fixed shape ?
3. What is liquid ?
4. Does liquids have fixed shape ?
5. Which one can change its shape of vessel ?

Question 24.
What are Aerosols ? Give any two examples.
Answer:

1. Aerosols are mixture of liquid or solid in gas.
2. Ex : Fog, Mist, Smoke.

Question 25.
Mention two properties of water to justify that water is liquid at room temperature.
Answer:
Water is liquid at room temperature as it takes the shape of the container in which it is put and it shows fluidity.

Question 26.
Gases are more compressible. Write two reasons for this.
Answer:
Gases are more compressible due to weak forces of attraction between molecules of gases and more intermolecular spaces.

Question 27.
Rate of diffusion is faster in gases. Why ?
Answer:

1. In case of gaseous state, due to negligible force of attraction they can move freely.
2. That is why rate of diffusion is faster in gases.

Question 28.
Sponge though compressible is a solid. Explain.
Answer:

1. In minute pores of sponge, air is trapped. When pressed, air is expelled out, so it is compressible.
2. It is a solid as it has definite shape and volume.

Question 29.
Rubber band though stretchable is a solid. Explain.
Answer:

1. Rubber band changes shape under force.
2. Rubber band regain shape when force is removed.

Question 30.
A wooden chair is solid at room temperature. Give two reasons.
Answer:

1. It has definite shape and volume.
2. It cannot be compressed.

Question 31.
Ice, water and steam are three states of a substances and not different substances. Justify.
Answer:
When ice is melted, water is produced and when water is heated, steam is produced. Conversely when steam is cooled, water is produced.

Question 32.
State all the factors that effect the rate of evaporation of water and also state how these factors affect it.
Answer:
Rate of evaporation increases with an increase in surface area, an increase in temperature, a decrease in humidity, an increase in speed of wind.

Question 33.
List any two properties that liquids have in common with gases.
Answer:
a) Gases and liquids do not have fixed shape.
b) Gases and liquids flow easily.

Question 34.
Give two reasons to justify that an iron almirah is a solid at room temperature.
Answer:
The shape does not change when pressed it is hard and rigid. It has a definite shape and has high density.

Question 35.
A diver is able to cut through water in a swimming pool. Which property of matter does this observation suggest ? How ?
Answer:

1. The particles of water are held together by weak forces of attraction.
2. It is these forces of attraction which the diver cuts through water in the swimming pool.

Question 36.
Explain the inter conversion of three states of matter in terms of force of attraction and kinetic energy of the molecules.
Answer:
During the inter conversion of a solid into a liquid and liquid into gas, on increasing the temperature the kinetic energy of the molecules increases and force of attraction among molecules decreases and vice-versa.

Question 37.
Why is oxygen called a gas ?
Answer:
Oxygen has neither fixed volume nor fixed shape. Oxygen exerts pressure due to collision of the molecules on the walls of containing vessel and among themselves.

Matter in Our Surroundings Class 9 Important Questions – 3 Marks

Question 1.
Write the properties of solids.
Answer:
Properties of solids:

1. All the solids have a definite shape, distinct boundaries and fixed volumes.
2. They have negligible compressibility.
3. Solids have a tendency to maintain their shape when subjected to outside force.
4. Solids may break under force but it is difficult to change their shape, so they are rigid.

Question 2.
Write the properties of liquids.
Answer:
Properties of liquids:

1. Liquids have no fixed shape but have a fixed volume.
2. They take up the shape of the container in which they are kept.
3. Liquids flow and change shape, so they are not rigid but can be called fluid.

Question 3.
Compare the following properties of solids, liquids and gases.
a) Shape
b) Volume
c) Compressibility
d) Diffusion
Answer:

Property	Solid	Liquid	Gas
Shape	Fixed	Attains the shape of container	No shape
Volume	Fixed	Fixed	No fixed volume
Compressibility	Very less	Intermediate	Maximum
Diffusion	Minimum	Intermediate	Maximum

Question 4.
How does diffusion survive the animals ?
Answer:

1. All living creatures need to breathe for survival.
2. The aquatic animals can breathe under water due to the presence of dissolved oxygen in water.
3. Solids and liquids can diffuse into liquids.
4. The gases from the atmosphere diffuse and dissolve in water.
5. These gases, especially oxygen and carbon dioxide are essential for the survival of aquatic animals and plant.

Question 5.
Mention the applications of compressibility in our daily life.
Answer:

1. Gas cylinders – gas is compressed and stored in cylinders.
2. Shaving cream is compressed, so it comes outside as a foam.
3. Due to the compressibility only medicines in syringe infected in to our body through needle.
4. Due to the compressibility property only liquids adjust themselves in a container.

Question 6.
What will happen to water when wet clothes dry up ?
(OR)
What is evaporation ? How does it take place ?
Answer:

• The phenomenon of change of a liquid into vapours at any temperature below its boiling point is called evaporation.
• In the case of liquids, a small fraction of particles at the surface, having higher kinetic energy, is able to break away from the forces of attraction of other particles and gets converted into vapour, this phenomenon is called evaporation.

Question 7.
Ravi: Water can change its state of liquid into vapour at 100°C only.
Is Ravi’s statement correct ? Explain.
Answer:

1. Ravi’s statement is wrong.
2. Water can change its state of liquid into vapour not only at 100°C but also at any temperature.
3. In evaporation, water can change into vapour at any temperature.
4. For example, water over a wet floor evaporates and dries up at temperature of below boiling point.

Question 8.
Give daily life examples to where we can feel the effect of cooling due to evaporation.
Answer:

1. We feel cool on the palm when we pour some acetone or nail polish remover on the palm.
2. After a hot sunny day, people sprinkle water on the roof or open ground because the large latent heat of vaporisation of water helps to cool the hot surface.
3. During summer, we perspire more because of the mechanism of our body which keeps us cool.

Question 9.
We can’t rejoin the broken chalk easily. Give reason.
Answer:

1. Force of attraction between the particles of the chalk is weak.
2. It is easy to break, but we can’t join.
3. To join two materials we need to let the molecules of two get near enough for the Coulomb forces to start acting.
4. That’s why any solid keeps its shape.
5. Liquids can’t keep its shape because the molecular distance in liquids is too large for this action.

Question 10.
How is compressibility of gases useful in our daily life ?
Answer:

1. The liquefied petroleum gas (LPG) cylinder that we get in our home for cooking or the oxygen supplied to hospitals in cylinders is compressed gas.
2. Compressed natural gas (CNG) is used as fuel these days in vehicles.
3. Due to its high compressibility, large volumes of a gas can be compressed into a small cylinder and transported easily.

Question 11.
During summer, we perspire more. Why ?
Answer:

1. During summer, we perspire more, because of the mechanism of our body which keeps us cool.
2. We know that during evaporation, the particles at the surface of the liquid gain energy from the surroundings or body surface and change into vapour.
3. The heat energy equal to the latent heat of vaporisation is absorbed from the body leaving the body cool.

Question 12.
The strength of this force of attraction varies from one kind of matter to another. Do you agree with it ? Explain with an activity.
Answer:

1. Take an iron nail, a piece of chalk and a rubber band.
2. Try breaking them by hammering, cutting or stretching.
3. We can observe that the particles are held together with greater force in iron nail than piece of chalk and rubber band.

Conclusion : The strength of this force of attraction varies from one kind of matter to another.

Question 13.
Take some finely powdered salt (not crystals) and keep it in two different jars. Which shape does the powdered salt take ?
Can you say that salt is a liquid on the basis of change in its shape ? Justify your answer.
Answer:

1. Powdered salt takes the shape of the container.
2. It is a solid.

Justification:

1. Change in shape or state means a complete change in the arrangement of particles.
2. Powdered salt is a composition of tiny particles, which do not change their shape.

Question 14.
2 ml of dettol is added to a beaker containing 500 ml of water and stirred. State four observations that you make.
Answer:

1. Level of water remains same.
2. The solution becomes white in colour.
3. Smell can be detected even on repeated dilution. ,
4. A true solution is obtained.

Question 15.
Define the following terms :
(i) Rigidity
(ii) Compressibility
(iii) Diffusion.
Answer:
i) Rigidity : It is the property of-matter to maintain shape against external force.
ii) Compressibility : It is the property of matter by virtue of which molecules of matter are brought closer to each other.
iii) Diffusion : The intermixing of the particles of matter is known as diffusion.

Important Questions on Matter in Our Surroundings Class 9 – 5 Marks

Question 1.
What are the factors that affect evaporation ? Explain.
Answer:
1) An increase of surface area : We know that evaporation is a surface phenomenon. If the surface area is increased, the rate of evaporation increases. For example, while putting clothes for drying up we spread them out.

2) An increase of temperature : With the increase of temperature, a greater number of particles get enough kinetic energy to go into the vapour state.

3) A decrease in humidity : Humidity is the amount of water vapour present in air. The air around us cannot hold more than a definite amount of water vapour at a given temperature. If the amount of water in air is already high, the rate of evaporation decreases.

4. An increase in wind speed : It is a common observation that clothes dry faster on a windy day. With the increase in wind speed, the particles of water vapour move away with the wind, decreasing the amount of water vapour in the surrounding.

Question 2.
Define Evaporation. On what factors does the evaporation depends on ?
Answer:
The conversion of a liquid into it’s vapour state is known as evaporation.

Factors effecting Evaporation:
1) Nature of the liquid :
• Lower the B.P. of a liquid higher the rate of evaporation.
2) Temperature of the Liquid :
• Higher the temperature of a liquid quicker the rate of evaporation.
3) Surface Area :
• Larger the surface area of a liquid, higher is its rate of evaporation.
4) Wind velocity:
• Higher the wind velocity quicker the rate of evaporation.

Question 3.
How is melting takes place ?
(OR)
What happens inside the matter during this change of state from solid to liquid ?
Answer:

1. On increasing the temperature of solids, the kinetic energy of the particles increases.
2. Due to the increase in kineticenergy, the particles start vibrating with greater speed.
3. The energy supplied by heat overcomes the forces of attraction between the particles.
4. The particles leave their fixed positions and start moving more freely.
5. A stage is reached when the solid melts and is converted to a liquid.
6. the minimum temperature at which a solid melt to become a liquid at the atmospheric pressure is called its melting point.

Question 4.
Rithyik took a bottle with ice-cold water from the refrigerator and placed on a table. Bharath poured petrol drops on his hand.
a) Write possible observations in two situations by them.
b) Write the differences between two phenomena involved in both cases.
Answer:
a) 1) Some water droplets will form on the ice-cold water bottle due to condensation of the surrounding humidity on the surface of the bottle.
2) Bharath will feel coolness on his hand where the petrol is poured due to evaporation of petrol by absorbing heat from the hand.

b) Differences between condensation and evaporation :

Condensation	Evaporation
In condensation gas changes into liquid.	In evaporation liquid changes into gas.
It occurs at specific temperature.	It occurs at any temperature.
It is a warming process.	It is a cooling process.

Question 5.
How do you prove that matter is made up of particles ?

Answer:

1. Take a 100 ml beaker.
2. Fill half the beaker with water and mark the level of water.
3. Dissolve some salt/ sugar with the help of a glass rod;
4. Observe any change in water level.
5. Observation : There is no change in water level.
6. Reason : When we dissolve salt in “water, the particles of salt get into the spaces between particles of water.
7. Conclusion : Matter is made up of particles. ,

Question 6.
How small are these particles of matter ? Demonstrate with an activity.

Answer:

1. Take 2 – 3 crystals of potassium permanganate and dissolve them in 100 ml of water.
2. Take out approximately 10 ml of this solution and put it into 90 ml of clear water.
3. Take out 10 ml of this solution and put it into another 90 ml of clear water.
4. Keep diluting the solution like this 5 to 8 times.
5. Observe the colour every time.
6. Observation : The water is still coloured.With every dilution, though the colour becomes light, it is still visible.
7. Reason : A few crystals of potassium permanganate can colour a large volume of water (about 1000 l)
8. Conclusion : So, we conclude that there must be millions of tiny particles in just one crystal of potassium permanganate, which keep on dividing themselves into smaller and smaller particles.

Question 7.
Do particles of matter move continuously ? Explain- with activities.
(OR)
Write activities to show diffusion.
Answer:
a) Gas particles diffuse in gas :

1. Put an unlit incense stick in a corner of your class.
2. Now light the incense stick.
3. Move away from the incense stick.
4. Observation : We can get the smell of incense stick.
5. Reason : Particles of incehSe stick moved and reached you.
6. Conclusion : Particles of matter move continuously. Gas particles diffuse in gas.

b) Liquid particles diffuse in liquid :

1. Take two glasses/beakers filled with water.
2. Put a drop, of blue or red ink slowly and carefully along the sides of the first beaker and honey in the same,way in the second beaker.
3. Leave them undisturbed in your house or in a corner of the class.
4. Record your observations.
5. Observation : The colour of ink spreads evenly throughout the water.
6. Conclusion : Liquid particles diffuse in liquid.

Question 8.
How do you prove that on heating, diffusion becomes faster ?
(OR)
Write activity to show diffusion of solid in liquid.
Answer:

1. Drop a crystal of copper sulphate or potassium permanganate into a glass of hot water and another containing cold water.
2. Do not stir the solution.
3. Allow the crystals to settle at the bottom.
4. Observation : The solid crystal particles move in entire liquid.
5. In hot water particles move faster than that of cold water.
6. Conclusion : Solid particles move in liquid.
7. We also conclude that on heating, diffusion becomes faster.

Question 9.
Prove that gases are highly compressible as compared to solids and liquids.
Answer:

1. Take three 100 ml syringes and close their nozzles by rubber corks, as shown in the given figure.
2. Remove the pistons from all the syringes.
3. Leaving one syringe untouched, fill water in the second and pieces of chalk in the third.
4. Insert the pistons back into the syringes.
5. You may apply some vaseline on the pistons before inserting them into the syringes for their smooth movement.
6. Now, try to compress the content by pushing the piston in each syringe.

Observation : We can push the piston of syringe with air easily than water and chalk. ,
Conclusion : Gases are highly compressible as compared to solids and liquids.

Question 10.
How do you find the boiling point and melting point of water ?
Answer:

• Take about 150 g of ice in a beaker and suspend a laboratory thermometer so that its bulb is in contact with the ice, as in the below figure.

• Start heating the beaker on a low flame.
• Note the temperature when the ice starts melting.
• Note the temperature when all the ice has converted into water.
• Record your observations for this conversion of solid to liquid state.
• Now, put a glass rod in the beaker and heat while stirring till the water starts boiling.
• Keep a careful eye on the thermometer reading till most of the water has vaporised.
• Record your observations for the conversion of water in the liquid state to the
  gaseous state.
• A stage is reached when the solid melts and is converted to a liquid. The minimum temperature at which a solid melts to become a liquid at the atmospheric pressure is called its melting point. The melting point of ice is 273.15 K.
• The temperature at which a liquid starts boiling at the atmospheric pressure is known as its boiling point. Boiling point of water is 373 K (100° C).

Question 11.
How do you show sublimation and deposition through an activity ?
Answer:

1. Take some camphor or ammonium chloride.
2. Crush it and put it in a china dish.
3. Put an inverted funnel over the china dish.
4. Put a cotton plug on the stem of the funnel, as shown in adjacent figure.
5. Heat slowly and observe.
6. We can observe that camphor directly changes into gas and the gas directly changes into solid.
7. A change of state directly from solid to gas without changing into liquid state is called sublimation and the direct change of gas to solid without changing into liquid is called deposition.

Question 12.
Write an activity to show that the rate of evaporation depends on surface area of. the liquid, wind speed and humidity.
Answer:

1. Take 5 ml of water in a test tube and keep it near a window or under a fan.
2. Take 5 ml of water in an open china dish and keep it near a window or under a fan.
3. Take 5 ml of water in an open china dish and keep it inside a cupboard or on a shelf in your class.
4. Record the room temperature.
5. Record the time or days taken for the evaporation process in the above cases.
6. Repeat the above three steps of activity on a rainy day and record your observations.

Observation and conclusion : If the surface area is increased, the rate of evaporation increases.
If the amount of water in air is already high, the rate of evaporation decreases.
If wind speed is increased, rate of evaporation increases.

Extra Questions on Matter in Our Surroundings Class 9 – 4 Marks

Question 1.
Jar – A contains water and jar – B contains fine sand Both water and sand get the shape of jar. We know that liquids have the shape of their containers.
Can you say both water and sand are liquid states ? Justify your answer.

Answer:

1. Water is liquid in the state, but sand is solid state.
2. Sand can get the shape of the container due to the fine and very small size of sand crystals.
3. But, the shape of each individual sand crystal remains fixed.
4. Hence the sta{e of sand is solid.

Question 2.
Madhuri doing the experiment which is showing in the figure.

i) Which chemical is placed in the China dish ?
ii) What is her observation ?
iii) Which phenomena involved in this experiment ?
iv) What happens if there is no cotton plug ?
Answer:
i) Ammonium Chloride.
ii) The vapours of ammonium chloride on the walls of the funnel.
iii) Sublimation and deposition.
iv) The vapours will escape through the top of the funnel.

Question 3.
Write four lines by observing the given figure.

Answer:

1. The change of liquid state to solid is called Solidification.
2. The change of solid state to gas is called Sublimation.
3. The change of gas state to liquid is called Condensation.
4. The change of liquid state to gas is called Vaporisation.
5. The change of gas state to solid is called Deposition.
6. The change of solid state to liquid is called Fusion.

Question 4.
Fill the table with suitable answers.

S.No.	Parameter	When increases/decreases	Rate of Evaporation increases /decreases
1.	Surface area of liquid	increases
2.	Humidity	increases
3.	Wind speed	increases
4.	Temperature		increases

Answer:

S.No.	Parameter	When increases/decreases	Rate of Evaporation increases /decreases
1.	Surface area of liquid	increases	increases
2.	Humidity	increases	decreases
3.	Wind speed	increases	increases
4.	Temperature	increases	increases

Question 5.
a) Let us stretch a rubber band. Is there a change in its shape ?
b) Is rubber band solid or liquid ? Why ?
Answer:

1. When rubber band is stretched it changes its shape.
2. It is a solid.
3. If stretching is stopped, the rubber band regains its shape.
4. If the stretching is too much, the rubber band permanently loses its shape.

Reason :

1. Rubber band is a solid, but the nature of particles by which the rubber band is made is responsible for the above phenomena.
2. Rubber and doesn’t get shape of vessel. So, it is not liquid. It is solid.

Question 7.
Based on the diagram answer the following questions.

i) Identify the process involved in the diagram.
Answer:
Sublimation.

ii) Is something missing in the diagram. If so what is that ?
Answer:
Stove is missed for heating.

iii) If ‘B’ represent ammonium chloride, then what is ‘A’ represent
Answer:
Mixture of ammonium chloride and salt.

iv) Give one more example for separation of mixture using above process ?
Answer:
Camphor and salt.