Question

an element has atomic number 10 and an atomic mass of 20. how many neutrons are in the atom of this element

Answer 1

Hey there!

n = A - Z

n =  20 - 10

n = 10 

Answer 2

Answer:

There are 10 neutrons in this atom of an element.

Explanation:

Atomic mass of an element  = 20

Atomic mass number is the sum of number of protons and neutrons that are present in an atom.

Atomic Mass number = Number of protons + Number of neutrons

Atomic number of an element = 10

Atomic number is the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons

Number of protons = 10

Atomic Mass number = Number of protons + Number of neutrons

20 = 10 + Number of neutrons

Number of neutrons = 10

There are 10 neutrons in this atom of an element.