Number of protons, neutrons and electrons in the element 89X^231 is

(a) 89, 89, 242
(b) 89, 142, 89
(c) 89, 71, 89
(d) 89, 231, 89

Question

Number of protons, neutrons and electrons in the element 89X^231 is

(a) 89, 89, 242
(b) 89, 142, 89
(c) 89, 71, 89
(d) 89, 231, 89

Accepted Answer

>

> [!TLDR]
> For a neutral atom written as (mass number)X(atomic number): protons = atomic number, neutrons = mass number - atomic number, electrons = protons.
>
> Here the atomic number (subscript, number of protons) is 89, and the mass number (superscript, protons + neutrons) is 231.
>
> - Protons = atomic number = 89 …

Notation	Element	Protons ( $Z$ )	Neutrons ( $N$ )	Mass Number ( $A$ )
$^{1}_{1}\text{H}$	Hydrogen	1	0	1
$^{4}_{2}\text{He}$	Helium	2	2	4
$^{23}_{11}\text{Na}$	Sodium	11	12	23

Q.Number of protons, neutrons and electrons in the element 89X^231 is

Concept understanding — Atomic Notation

Atomic Notation: The ID Card of an Atom

The Intuition: Three Numbers, One Symbol

The Precise Statement

Example: Carbon-12

Why Two Numbers? Why Not Just One?

A Quick Table for Clarity

Q.Number of protons, neutrons and electrons in the element 89X^231 is

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