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Potassium has an atomic number

of 19 and a mass number of 39.
How many neutrons does a
Potassium atom have?
A. 18
B. 19
C. 20

User Andrew W
by
3.5k points

2 Answers

7 votes

Answer:

20 neutron

Step-by-step explanation:

neutron=atomic mass-atomic no.

=39-19

=20

User Venu A Positive
by
3.5k points
4 votes
Answer: C) 20

Detailed Explanation:

No. of Neutrons = Mass No. - Atomic No.

Therefore,
= 39 - 19
=> 20

No. Of Neutrons = 20
User Earachefl
by
3.4k points