Atomic Number = 21
Atomic Mass = 45
Therefore, number of protons = 21
number of electrons = 21
number of neutrons = 45-21
=45-21=24
An atom X is represented as follows {}_{21}^{45} ext{X}. The numbers of protons, electrons and neutrons in this atom are:
a) 21, 21, 24 b) 21,21,23 c) 20,20,24 d) 20,20,23
-
UP 0 DOWN 0 1 3
3 Answers
Meghna Guha
·2014-05-01 05:34:08
mass number is 45 and atomic number is 21. so number of neutrons should be 45-21=24
Anurat Bhattacharya
·2014-05-03 07:02:33
Atomic no 21,mass no =45
So no of protons=21
electrons=21
nuetrons=45-21
Angikar Ghosal
·2014-05-05 09:14:12