Science 1 Marks Question

Can we call the breaking down of ozone a chemical change?

Is neutralisation a chemical change?

Is digestion process a chemical change?

We learnt in chapter 1 that plants produce their food by a process called photosynthesis. Can we call photosynthesis a chemical change?

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

What kind of change is shown by tearing of paper?

Why cannot a chemical change be normally reversed?

Name the metals, which are mixed (alloyed) with iron to make stainless steel.

Suggest two methods to prevent rusting.

Write word equations for two chemical reactions with the help of materials given in the box.
(Air, copper sulphate, iron, vinegar, iron oxide, carbon dioxide, iron sulphate, copper, lime water, water)

Write the colour of copper sulphate solution obtained when Iron nails are dipped in it?

Name the gas, which turns lime water milky.

We should eat freshly cut apple. Why?

How can you say that ripening of a fruit is a chemical change?

What is the nature of magnesium oxide solution?

What colour of flame is observed when magnesium ribbon burnt in air?

Give example of a physical change, which occurs by the action of heat.

Which gas is given off when calcium carbonate is heated?

For which purpose sand paper is used?

What method will you use to get a pure liquid if it has dissolved impurities present in it?