Calculate the number of protons, electrons, and neutrons in an atom of the element Pb with mass number 207 and atomic number 82. # P= #E= # N=

Question

asked Oct 4, 2020 173k views

1 Answer

Josh K · Answer 1 · 2020-10-10T07:25:26+0000

Step-by-step explanation:

Let
be the number of protons.

Let
be the number of electrons.

Let
be the number of neutrons.

Atomic number is defined as the number of protons in a atom or ion.

Given,atomic number is
.

So,
p=82

Since the atom is electrically neutral,number of protons and electrons are equal.

So,
e=p=82

The atomic mass is the sum of neutrons and protons.

$n+p=207\\n=207-82\\n=125$