Sound — Science STD 9 — Question

How is the size of an atom indicated?

Write the symbols/ formulae of two simple ions and two compound ions (or polyatomic ions).

How many molecules are present in one gram molecular mass of a substance?

What is the common name of '1kWh' of electrical energy’?

What is the relation between pressure, force and area?

Name the characteristic of sound which can distinguish between the ‘notes’ (musical sounds) played on a flute and a sitar (both the notes having the same pitch and loudness).

What is the usual symbol for (a) an electron (b) a proton, and (c) a neutron?

Name that part of ear which vibrates when outside sound falls on it.

Name the subatomic particle whose relative charge is:

1. +1
2. -1
3. 0

Name the law of chemical combination:
Which was given by Proust.