Question

An atom with 19 protons, and 19 electrons and a mass of 39 has how many neutrons?

Answer 1

Answer + Explanation:

For potassium it is about 39.

Since we know that the number of protons is 19 we can calculate the number of neutrons (39 19) as 20.

Answer 2

Answer :-

• The number of neutrons is 20.

Step-by-step explanation :-

To Find :-

• Number of neutrons of an atom.

Solution :-

Given that,

• Number of protons of atom = 19
• Number of electrons of atom = 19
• Mass number of atom = 39

As we know that,

Mass number = Number of protons + Number of neutrons,

Therefore,

➞ Number of protons + Number of neutrons = Mass number

➞ Number of neutrons = Mass number - Number of protons

➞ Number of neutrons = 39 - 19

➞ Number of neutrons = 20

Hence,

• The number of neutrons is 20.

Know more :-

Some more information related to atomic number and mass number :-

• Atomic number = Number of protons = Number of electrons

• Mass number = Number of protons + Number of neutrons

• Number of neutrons = Mass number - Number of protons.