Science 1 Marks Question

Is curdling of milk a physical or chemical change? Justify your statement.

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Forming of soil from rocks

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Rolling up a mat

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Boiling water in an open pan

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Ripening of fruits

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Drawing water from a well

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Grinding wheat grains to flour

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Dissolving sugar in water

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Making idlis from a batter

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Twisting of straight string

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Stitching cloth to a shirt

Note the changes in shape, size or state : Making pot from mud

Note the changes in shape, size or state : Cooking of food

Note the changes in shape, size or state : Rolling small balls of dough into chapatis

Note the changes in shape, size or state : Making small balls of dough

Note the changes in shape, size or state : Drying wet clothes

Note the changes in shape, size or state : Burning wood

Note the changes in shape, size or state : Adding beetroot extract to water

Note the changes in shape, size or state : Cutting a piece of paper

Note the changes in shape, size or state : Making popcorn from corn

Note the changes in shape, size or state : Boiling water

Note the changes in shape, size or state : Chopping vegetables

Note the changes in shape, size or state : Melting ice cubes

Name two desirable changes.

Gives examples of natural slow changes.

What is the colour of rust?

When baking soda is mixed with vinegar then a gas is released. Name the gas.

Define ignition temperature.

During rusting, which new substance is formed?

What is the colour of flame when magnesium ribbon is burnt?

Give two examples of a chemical change.

Combustion, cooking, and rusting are chemical changes, justify the statement.

What type of change is called in which new substance with new properties is formed?

Give two examples for each of the following cases:
(a) Physical changes which are reversible.
(b) Physical changes which are not reversible.
(c) Chemical changes.

The gas we use in the kitchen is called liquefied petroleum gas (LPG). In the cylinder it exists as a liquid. When it comes out from the cylinder it becomes a gas (Change-A) then it bums (Change-B). Identify change A and change B.

What are combustible substances? Give two examples.

List conditions under which combustion can take place.

What is chemical change?

What are physical properties?

Melting of butter is reversible or irreversible change?

What happens when we add beetroot extract to water?

Define the term bioluminescence.

Define combustion.

What happens when carbon dioxide is passed through lime water? Write the equation of the reaction.

Name the gas released when baking soda is mixed with vinegar.

What do you mean by rusting?

Melting of wax is a change where a solid changes to liquid state. Give one more such change which you observe in your surroundings.

If you cut off a paper into various pieces, is there any change in the property of the paper?

What are the two main kinds of changes?

Changes listed in A, B and C are as follows :
A. Creating some objects with paper: When we create different objects like aeroplane, boat, bird, etc. by folding a sheet of paper, only shape and size changes. We can get back the original sheet by unfolding it again.
B. Playing with a balloon: When we loosen the grip of the inflated balloon we get the original shape of balloon back, and we can inflate it again but when we prick the inflated balloon with a pin, it gets deflated with a hole in it, so we cannot able to inflate it again.
C. Crushing a piece of chalk: When we crushed a piece of chalk to powder form, we cannot can get back the original piece of a chalk.

What is combustion?

Can a chemical change be reversed? Give an example.

What happens when you heat water in an open pan?

Give an example of a chemical change in daily life.

What happens when magnesium is burnt in air?

What is the significance of the turning of lime water milky during a chemical reaction?

How can you test the presence of carbon dioxide?