Question

How many protons are in an element with an atomic number of 8 and a mass number of 18?

Question 5 options:

3


18


10


8

Answer 1

the answer is 8. atomic number: the number of protons in the nucleus of an atom.

Answer 2

Answer : The number of protons in an element are 8.

Explanation :

Atomic number is defined as the number of protons or number of electrons.

Atomic number = number of protons = number of electrons

Mass number is defined as the sum of number of protons and number of neutrons.

Number of neutrons = Mass number - Number of protons

As we are given :

Atomic number of an element = 8

Mass number of an element = 18

Now we have to determine the number of protons for this element.

As, Atomic number = number of protons = number of electrons

So,

Atomic number = Number of protons = 8

Hence, the number of protons in an element are 8.