set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

A radioactive element X emits an α-particle followed by 2 β-particles in the successive steps as :
X $⟶↖{λ_1} ↙{-α particle} Y ⟶↖{λ_2} ↙{-2β particles} Z$
Which of the following statement(s) is/are correct?

1. Y and Z are isotopes
2. The atomic number of X and Z are the same
3. Y and Z are isobars
4. The mass number of Y is greater than X

a) 1 and 4

b) 2 and 3

c) Only 1

d) Only 3

Question : 2

Elements of which group form anions most readily?

a) Nitrogen family

b) Halogens

c) Oxygen family

d) Alkali metals

Question : 3

Most of the explosions in mines occur due to the mixing of

a) oxygen with acetylene

b) methane with air

c) hydrogen with oxygen

d) carbon dioxide with ethane

Question : 4

Which is a metalloid?

a) Sb

b) Bi

c) Pb

d) Zn

Question : 5

The early attempt to classify elements as metals and nonmetals was made by

a) Lother Meyer

b) Lavoisier

c) Mendeleev

d) Henry Moseley

Question : 6

A woman desires to clean the surface of her gold ornaments by a chemical approach. For this she requires to use

a) concentrated H₂SO₄

b) concentrated NaOH

c) aqua-regia

d) sodium thiosulphate solution