Question

1. If the atomic number is 25, how many protons does it have?
2. If the atomic mass is 55 (rounded) and mass= protons + neutrons, how many neutrons does it have?

Answer 1

Remember the atomic number is equal to the number of protons and electrons. (in an element)

2. Well if mass is 55 what element is it (look at the period table). Now that you know the element, you know how many protons are in it, now how many electrons are left to make up the atomic mass?

Answer 2

hmmm. do you know what determines the atomic number?
then, protons+neutrons=55, so if you have the protons, getting the neutrons is easy ... right?

Answer 3

Thanks