atomic structure molecules and nuclear chemistry - Category wise Question and Answer Practice Test with Solutions

Question : 11 [NDA]

What is the number of water molecules present in a tiny drop of water ( volume 0.0018 ml ) at room temperature?

a) 6.023 × 10¹⁹

b) 4.184 × 10¹⁸

c) 4.84 × 10¹⁷

d) 6.023 × 10²³

Question : 12 [UPPCS (Pre) 2007]

Which of the following is not a subatomic particle?

a) Proton

b) Deuteron

c) Neutron

d) Electron

Question : 13 [IAS (Pre) 2001]

In an atom, the order of filling up of the orbitals is governed by

a) Heisenberg’s uncertainty principle

b) Hund’s rule

c) Aufbau’s principle

d) Pauli’s exclusion principle

Question : 14 [NDA]

The atomic weights are expressed in terms of atomic mass unit. Which one of the following is used as a standard?

a) ¹⁶O₈

b) ¹²C₆

c) ¹H₁

d) ³⁵Cl₁₇

Question : 15

Which of the following describes an isotope with a mass number of 99 that contains 56 neutrons in its nucleus ?

a) $↖43↙56{Ba}$

b) $↖99↙43{Tc}$

c) $↖99↙56{Ba}$

d) $↖56↙43{Tc}$