How many neutrons does element X have if its atomic number is 25 and its mass number is 85?

60 neutrons

Step-by-step explanation:

We are given that the atomic number of an element X is 25 and its mass number is 85 and we are find the number of neutrons this element has.

We will use the following formula to find the number of neutrons:

Neutrons = Atomic mass number - Atomic number

So substituting the given values in the above formula to get:

Number of neutron = 85 - 25 = 60

Therefore, element X has 60 neutrons.

Neutrons = Atomic Mass Number - Atomic Mass Number

So 85-25 = 60