Light — Science STD 8 — Question

Testes produce male germ cells. What are these cells called? Name its parts.

What type of oxides are formed? When non-metals combine with oxygen?

Name any two devices used in everyday life which work on the existence of atmospheric pressure.

How do the irrigation requirements of a wheat crop differ from that of a paddy crop?

An archer stretches her bow while taking aim at the target. She then releases the arrow, which begins to move towards the target. Based on this information, fill up the gaps in the following statements using the following terms: muscular, contact, non-contact, gravity, friction, shape, attraction
(a) To stretch the bow, the archer applies a force that causes a change in its ____________ .
(b) The force applied by the archer to stretch the bow is an example of ____________ force.
(c) The type of responsible for a change in the state of motion of the arrow is an example of a ____________ force.
(d) While the arrow moves towards its target, the forces acting on it are due to ____________ and that due to ____________ of air.

Why are metals used for making bells?

Explain the difference between viruses and bacteria.

Name the scientist who showed that lightning is electric in nature.

At which temperature, a substance catches fire and starts burning?