Previous Year Questions
CLASS - IX Science (Structure of Atom)
1.
Atomicity of fluorine is :-
2.
Molecular formula for calcium fluoride is –
(a) Ca F2
3.
(a) 1
(b) 2
(b) Ca F
(c) 3
(d) 4
[1]
(c) Ca2 F
(d) 2 Ca F
Electronic configuration of calcium is
(a) 2, 8, 8, 2
[1]
(b) 2, 8, 6, 4
(c) 2, 8, 7, 1
Nitrogen is :- (a) Monatomic
5.
Which of the following electronic configuration are wrong and why?
(b) 2, 8, 8, 2
(b) Diatomic
(d) 2, 8, 1, 7.
4.
(a) 2, 8, 2
[1]
(c) Triatomic
(d) Tetratomic
[1]
[2]
(c) 2, 8, 9, 1.
6.
What are ions? What are its two types?
[2]
7.
Show diagrammatically the formation O2- ion?
[2]
8.
Define Isotopes and Isobars?
[2]
9.
Find the percentage composition of sucrose ( C12 H 22O11 ) .
[3]
10.
Complete the following Table :
[3]
Ion
11.
a)
86
Rb + 37
B)
24
Mg 2+12
c)
80
Br − 35
Number of
Atomic
Number of
Atomic
electrons
Number
Neutrons
Mass
Calculate
[3]
a) The number of gram – atoms of oxygen
b) The number of atom of oxygen
c) The number of molecules of ozone in 32 g of ozone [O3]
12.
What mass of water will contain the same number of molecules as 8,0g of ferrous
oxide [FeO] ?
[3]