(a) Write the chemical symbols of two elements : (i) which are formed from the first letter of the elements name. (ii) whose name has been taken from the names of the elements in Latin. (b) Define Avogadro's constant and molar mass

CBSE Class 9 CBSE Class 9 Science
1

(a) Write the chemical symbols of two elements :
(i) which are formed from the first letter of the elements name.
(ii) whose name has been taken from the names of the elements in Latin.
(b) Define Avogadro’s constant and molar mass. How are they related to one mole of an atom, molecule, orion ?

2

(a) (i) C, N, O, etc.
(ii) Na, Fe, K, etc.
(b) Avogadro’s constant:
6.22 x 10^23 is defined as the Avogadro’s constant. It is the number of atoms in exactly 12 g of carbon-12.

Molar mass: Mass of 1 mole of a substance.