Chemistry > Structure of Atom > 5.0 Atomic Number and Mass Number and It's Relation
Structure of Atom
1.0 Introduction
2.0 Cathode Ray Discharge Tube
3.0 Thomson Model of Atom
4.0 Rutherford Model of Atom
5.0 Atomic Number and Mass Number and It's Relation
6.0 Planck's Quantum Theory
7.0 Bohr’s Atomic Model
8.0 Dual Behaviour of Matter
9.0 Heisenberg Uncertainity Principle
10.0 Photoelectric Effect
11.0 Atomic Spectra
12.0 Quantum Mechanical Model of Atom
13.0 Quantum Number
14.0 Electronic Configuration of Elements
14.1 Aufbau (or building up) Principle
14.2 Pauli’s Exclusion Principle
14.3 Hund’s Rule
14.4 Stability of Completely Filled and Half Filled Subshells
5.3 Isotones
14.2 Pauli’s Exclusion Principle
14.3 Hund’s Rule
14.4 Stability of Completely Filled and Half Filled Subshells
Atoms with same number of neutrons.
Example: ${}_1^3T$ and ${}_2^4He$ are isotones.
Isoelectronic
Atoms with same number of electrons.
Example: $N{a^ + }$ and $A{l^{3 + }}$
Question 1. An atom having atomic mass number 13 has 7 neutrons. What is the atomic number of the atom?
Solution: $$\begin{equation} \begin{aligned} \Rightarrow A = 13,\;n = 7 \\ {\text{Mass number }}(A) = Z + n \\ \Rightarrow Z = 13 - 7 \\ \Rightarrow Z = 6 \\ {\text{Atomic Number }}(Z) = 6 \\\end{aligned} \end{equation} $$
