Stars and the Solar System — Science STD 8 — Question

Iron metal reacts slowly with the oxygen and moisture of damp air to form rust. State whether the rust formed is acidic, basic or neutral.

Can you imagine being able to walk at all, if there were no friction?

Name the star (after the Sun) which is closest to the Earth.

Which gas in the atmosphere traps the heat rays reflected by the earth?

The right meal for adolescents consists of.

Two glass jars A and B are filled with carbon dioxide and oxygen gases respectively. In each jar, a lighted candle is placed simultaneously. In which jar, will the candle remain lighted for a longer time and why ?

Name any two parts which are present in a plant cell but not in an animal cell.

Write some disadvantages of force of friction.

What is the significance of interparticle spacing in matter?

Out of two sexes of humans, which one has a longer reproductive phase of life ?