Page 3 - HA

d) Kalium
Q4 Assertion: One atom of Sodium can be represented as Na 1
Reason: The symbol of an element represents one atom of it.
Q5 Assertion: 2H represents one molecule of Hydrogen. 1
Reason: The molecular formula of a substance represents one
molecule of it.
Q6 The symbol of an element is always represented as the first letter of its 1
name. (True/False).

Concept: Atomic & relative atomic masses
Q1. Assertion: The atomic mass of oxygen is 16 u. 1
Reason: Mass of one atom of oxygen is 16 g.
Q2 Assertion: Atomic mass of Chlorine is 35.5 amu. 1
th
Reason: One atom of Chlorine is 35.5 times heavier than 1/12 of the
12
mass of one atom of C .
12
Q3 Assertion: 1 amu is equal to 1/12th of the mass of one atom of C . 1
Reason: The masses of atoms are compared with the mass of one
atom of the most stable isotope of Carbon.
Q4 What is the relative atomic mass of Sulphur? 1

a) 35.5 u b) 2 u
b) 32u d)16 g

Q5 What is the relative atomic mass of Magnesium? 1

a) 24 g
b) 24 u
c) 12 u
d) 16 u

Q6 The relative atomic mass of Nitrogen is 14 u that means one atom of 1
Nitrogen is 14 times heavier than one atom of Hydrogen which is taken
as a standard ( True/False)

Concept: Ions ( positive ion and negative ion), calculations of valency
of ions,
Writing of chemical formulae of the compounds
2+
Q1. Assertion: The formula of Ferrous ion is Fe 1
Reason: Iron has a variable valency.
Q2 Assertion:The formula Calcium oxide is CaO 1
Reason: The valencies of both Calcium and Oxygen is 2.
Q3 Assertion: The formula of the oxide of a metal XO and the formula of 1
its Chloride will be X Cl
Reason: The valency of the metal is 2 and Chlorine is also 2.
Q4 What is the valency of Iron in Fe 2O 3? 1