atomic structure (periodic table)

Question 1

atomic number (Z)

Answer 1

number of protons in nucleus of an atom

equal to number of electrons surrounding nucleus

Question 2

neutron number (N)

Answer 2

number of neutrons in atom

Question 3

atomic mass (A)

Answer 3

total mass of an atom

sum of proton and neutrons in nucleus

Question 4

isotopes

Answer 4

atoms of the same element that have the same Z(atomic number) but a different A (atomic mass)