- AAtomic number
- BMass number
- CFormula mass number
- DValency
Explanation:
The mass number (A), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. This is not the same as the atomic number (Z) which denotes the number of protons in a nucleus, and thus uniquely identifies an element.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

$2 A ( g ) + B ( g ) \rightleftharpoons C ( g )+ D ( g )$
Which of the following will not affect the equilibrium?
$Cu ( s )+2 Ag ^{+}( aq ) \rightleftharpoons Cu ^{2+}( aq )+2 Ag ( s )$
The equilibrium constant for the reaction.$\frac{1}{2} Cu ^{2+}( aq )+ Ag ( s ) \rightleftharpoons \frac{1}{2} Cu ( s )+ Ag ^{+}( aq )$ is $x \times 10^{-8}$. The value of $x$ is (Nearest Integer)