Diversity In Living Organisms — Science STD 9 — Question

Dalton’s atomic theory says that atoms are indivisible. Is this statement still valid? Give reasons for your answer.

Name two processes which provide the best evidence for the motion of particles in matter.

What name is given to the repetition of sound caused by the reflection of sound waves?

What is the reason for the identical chemical properties of all the isotopes of an element? Explain with the help of an example.

Name the process which can be used to separate a mixture of salt solution and sand.

From a rifle of mass 4kg, a bullet of mass 50g is fired with an initial velocity of 35m s^-1 . Calculate the initial recoil velocity of the rifle.

If an element M has mass number 24 and atomic number 12, how many neutrons does its atom contain?

What do we call those particles which have:
Less electrons than the normal atoms?

Long white eggs are produced by ________.