These TS 6th Class Science Important Questions 10th Lesson Changes Around Us will help the students to improve their time and approach.
TS 6th Class Science Important Questions 10th Lesson Changes Around Us
Question 1.
How do colours change?
Answer:
When substances of different colours are mixed, a new substance with a different colour may be formed. This is a reason for the change of colour.
Question 2.
Why do some substances appear coloured?
Answer:
A coloured substance absorbs some components of white light (VIBGYOR) and reflects the remaining colours. For example, a red book absorbs all the components of the white light except red (absorbs VIBGYO only). So the book reflects red light only. So the book appears red to our eyes.
Question 3.
What can be the reasons for the changes taking place, when milk changes to curd?
Answer:
Reasons:
- The reason for change of milk into curd is due to addition of some curd to warm milk.
- This added curd helps to grow some kind of bacteria in it and enables convertion of the milk into curd. Curd is a milk protein.
Question 4.
What changes do you observe from winter season to summer season?
Answer:
- The winter season is cool and summer season is hot.
- In winter, duration of night is longer than in summer.
The above changes are because of changes in seasons.
Question 5.
Which changes could possibly be the causes for the change in seasons?
Answer:
i. Seasons are caused because of earth’s inclination. It is inclined at an angle of 23! degrees to the orbit of its rotation around the sun. The earth is at four different places in the above figure. The sun is in the middle. The earth is away from the sun in different distances. The axis of the earth is inclined (we can observe it 23 \(\frac{1}{2}\)°) Seasons are caused because of earth’s inclination.
ii. Seasons change, because of revolution of the earth round the sun. The sun does not exactly rise in the east every day. It changes slightly every day. The slight change in the direction of the sunrise is also a reason for changes in seasons.
Question 6.
What is the duration of longest day in December?
Answer:
11 hours 11 minutes (17: 40-06 : 29).
Question 7.
What is the duration of longest day in May?
Answer:
13 hours 5 minutes (18 : 46 – 5 : 41).
Question 8.
Do December and May belong to the same season ? If not, to which seasons do they belong?
Answer:
No. December belongs to winter season. May belongs to summer season.
Question 9.
Does the sun rise exactly in the east in all seasons? Explain.
Answer:
No.
- Around 20th December the direction of sunrise is a little south of east.
- Around 15 May, the direction of sunrise is very close to the east.
Question 10.
Are there differences in the duration of day and night everyday? If so, why?
Answer:
- Yes. There are differences in the duration of day and night everyday. We do not find ‘day’ and ‘night’ of equal duration everyday.
- Reason : The axis of the earth is inclined at an angle of 23 degrees to the plane of its orbit. Hence we do not find day and night of equal duration every day.
Question 11.
Statements: Milk changes to curd. Seasons change.
i. Which change is slow and which is fast? Why?
Answer:
Change of seasons is slow when compared to change of milk into curd.
Reason:
- Every season extends for 4 months. So change of seasons is a slow process.
- Curdling of milk is a chemical reaction initiated by bacteria. Chemical reactions take place quickly.
ii. Which change takes place naturally?
Answer:
Change of seasons. It is related to the earth and its revolution around the sun.
iii. Which change needs initiation I intervention of human beings to occur?
Answer:
Change of milk to curd needs initiation and intervention from human beings. Because we have to add some curd to warm milk and keep it undisturbed for sometime.
iv. Which is a temporary change and which is permanent?
Answer:
Seasonal changes are temporary because these changes are continuous as shown below. winter
Question 12.
Is it possible to classify certain changes? How would you classify?
Answer:
- It is possible to classify certain changes.
- The changes can be classified based on some grounds.
Ex : Slow changes – Fast changes; Natural changes – Man-made changes; Temporary changes Permanent changes; Physical changes – Chemical changes; Reversible changes – Irreversible changes etc.
Question 13.
Write the indicators and causes for the changes given below.
Answer:
Indicators of change are – colour, taste, state, smell etc.
i. Change of ice into water and water into ice.
Indicators of change: Physical state, colour
These two states of matter differ in their state and also differ in appearance.
Reason for change : When ice absorbs heat, it melts and gives water. When water is cooled to 0°C, it loses heat and changes to ice.
ii. Rusting of Iron : Indicators of change : Change in colour, hardness of metal, formation of layers.
When iron rusts, a reddish brown coating is formed on it. It converts into a loose layer and detaches after sometime. Thus iron decays gradually.
Reason for change : In presence of sunlight, moisture and air, iron reacts with oxygen of air and moisture (water vapour present in air). Then the iron converts into a new substance, called rust (hydrated ferric oxide).
iii Growth in plants:
Indicators of change: Height of plant, number of leaves, hardening of its stem.
Reason for change : Availability of water, fresh air, sun-light, nutrients etc.
iv. Rice to cooked rice:
Indicators of change : Physical state, appearance, smell, stickiness.
Reason for change : The solid rice absorbs water and turns to semi-solid. white sticky mass. The volume also increases due to absorption of water. Cooked rice has a different smell.
v. Melting of Ice- Cream:
Indicators of change : Physical state.
Reason for change : Absorption of heat from the surroundings by the ice-cream.
vi. Boiling the egg in water:
Indicators of change : Size of egg, hardness, weight.
Reason for change : The contents of the egg convert into a soft solid mass from semi solid form, due to heat.
vii. Electric bulb on and off:
Indicators of change : Emission of light, consumption of electrical energy.
Reason for change : When switched on, electricity flows through the filament of the bulb. The filament gets heated up. This hot filament emits light. Here, electrical energy changes into heat energy and then to light energy.
viii. Changes in Atti Patti plant (Touch – me – not plant) : When we touch (a physical action) the attipatti plant, chemical change occurs inside the leaves and the leaves get folded.
Question 14.
Mention one change you observe in nature.
Answer:
Growth of fresh leaves on plants.
Question 15.
Mention one change you observe in our body.
Answer:
Increase in height.
Question 16.
What is the physical state of curd?
Answer:
A semi-solid.
Question 17.
Which enables conversion of the milk into curd?
Answer:
A kind of bacteria.
Question 18.
Which type of clothes do we like to wear in summer?
Answer:
Cotton clothes.
Question 19.
Does the sunrise exactly in the same place on all the days?
Answer:
No.
Question 20.
Does the sun rise exactly in the east in all seasons?
Answer:
No
Question 21.
Why days and nights are formed?
Answer:
Because of the rotation of earth on its own axis.
Question 22.
Why seasons are formed?
Answer:
Because of earth’s inclination.
Question 23.
What questions will you ask your teacher to know about any change that occurs in the nature?
Answer:
- What has changed?
- How do we know that it has changed?
- What are the possible reasons for that change?
- Which seems to be the most appropriate reason?
- How would we check if the reason is correct?
Question 24.
If changes do not occur in nature, what would be the consequence?
Answer:
We can’t imagine our life without occurrence of changes in nature Absence or lack of changes make us suffer from availability of food, shelter, water, protection etc. Not only man but also other living things will struggle due to absence of changes.
Question 25.
Are there any other properties by which you can categorize the above changes?
Answer:
They can be further categorized based on properties like:
- Physical change – Chemical change.
- Reversible change – Irreversible change.
- Colour change.
Question 26.
Do you know how milk can be converted into curd?
(Or)
How can milk be converted into curd ? Explain.
Answer:
Curdling of Milk:
- Milk is heated gently to boiling and allowed to cool.
- To the warm milk, a very small quantity of curd (sample curd) is added and stirred well.
- The vessel is kept undisturbed for a few hours.
- Then a white semi-solid mass appears in the vessel. It is curd.
Question 27.
What changes do you see when milk is converted into curd?
Answer:
When milk changes to curd, there is change in the colour, taste and in the state.
Colour : Though both milk and the curd appear white, there is a slight difference in their colours.
Taste: Milk is some what sweet and curd is slightly sour to taste.
Physical state : Milk is a liquid. Curd is a semi-solid.
However, the weights and volumes of the two substance remains the same.
Question 28.
What changes do you observe when the season changes?
Answer:
The following changes we observe when the season changes.
- Change in temperature.
- Direction of the sun.
- Humidity condïtions in the weather.
- Change in wearing type of clothes.
- Change in duration of day and night.
Question 29.
Observe the following table and answer to the questions given below.
Answer:
Questions:
a. Write about any one man made change?
b. What are the natural changes?
c. What are the permanent changes?
d. Why boiled egg is permanent change?
Answer:
a. Rice to cooked rice is a man made change.
b. Changes in seasons, rusting of iron, growth in plants, changes in Atti patti plant, Milk to curd, melting of ice-cream. Changes that occur themselves in the nature are called natural changes.
c. Milk to curd, egg to boiled egg, rusting of iron, growth in plants, rice to cooked rice, Melting of
ice-cream. The change that occurs in the matter and never come back to its original state is called permanent change.
d. Raw egg has shed with liquid yolk. After boiling yolk (liquid part) becomes solid substance.
Question 30.
Observe the following table and answer to the questions given below.
1. Which month had minimum rainfall?
Answer: Month of April had minimum rain fall.
2. August occurs In which season ? How can you support your answer?
Answer: Rainy season occures in the month of August because the rainfall is more in this month.
Question 31.
Read the following table and answer the questions.
Answer the following questions:
i. Which month was recorded with lowest temperature? How much?
Answer: Month of January was recorded with lowest temperature. The recorded temperature was 21°C.
ii. In which month the duration of the day the time was maximum?
Answer: In the month of April duration of day was maximum.
iii. What changes do you identify ¡n January to April?
Answer: Winter season changes into summer season.
iv. Which season occurs in the month of April ? What changes takes does in this season?
Answer: Summer season is seen in April. Climate become very hot.
Question 32.
Ramesh has observed the changes and filled the table. Can you do this?
a. In the above changes which are natural and permanent changes?
Answer:
Rusting of iron and growth in plants are natural and permanent changes.
b. Which of the above changes are man made?
Answer:
Change from milk to curd and boiling of egg are man made changes.
Question 33.
Observe the table and answer the following questions.
Answer:
i. How many changes are natural?
Answer: Six.
ii. How many are man-made?
Answer: Five
iii. How many changes are temporary?
Answer: Five.
iv. How many are permanent?
Answer: Five.
v. How many changes are slow?
Answer: Slow’ is a relative term.
vi. How many are fast?
Answer: ‘Fast’ is a relative term.
List the changes in the following table.
Answer:
Question 34.
Observe the below pictures. Give a brief explanation about curdling of milk in which vessel we will see curd ? why?
Answer:
Answer:
- The vessel with luke warm milk and butter milk drops will have curd.
Luke warm condition of milk enables curd. - Where as two vessels with cool milk and hot boiled milk cannot bring the change.
- The temperature is the factor that helps in curdling of milk.
Question 35.
Observe the given pictures. Write your conclusion?
Answer:
It is concluded that the sun does not rise exactly in the east in all seasons. In summer it rises exactly in the east. During winter it rises in little south of east.
Question 36.
How changes that occur in the nature keep the man in a comfortable living conditions?
Answer:
- Changes in the seasons help the man growing crops in the field.
- Different seasonal changes from rainy season to summer season help to harvest different types of crops.
- Changing milk into curd is an amazing fact. Microbes bring the change in milk.
- Changes in seasons help the man to protect health from various diseases.