Class 9 Chemistry MCQ Chapter 2

________________ orbital is more complex in shape.

s

p

f

d

The isotopes of an element have different number of

Electrons

Protons

Neutrons

Protons & Neutrons

Energy of a shell is ________________

Variable

Constant

Cannot be changed

Nil

Which of the following result in discovery of proton?

cathode rays

canal rays

x-rays

alpha rays

Alpha particles are double charged.

Negative

Positive

Can be both

Nil

In isotopes numbers of ________________ is same.

Protons

Electrons

Neutrons

Mass number

According to Bohr, electrons can revolve only in this orbits whose angular momentum is

h/2π

n 2h/π

n h2/2π

n h/2π

Deuterium is used to make:

light water

heavy water

soft water

hard water

Atoms of elements combine chemically to form:

Mixtures

compounds

solutions

ions

For diagnosis of goiter in thyroid gland we use

Co-60

C-14

I-131

Sr-90