Question

1. the table below describes four atoms.

atom a atom b atom c atom d
number of protons 79 80 80 79
number of neutrons 118 120 118 120
number of electrons 79 80 80 79
which atoms represent the same element?
c and d represent the same element
a and d represent the same element
a and c represent the same element
a and b represent the same element
b and c represent the same element

Explanation:

Elements are defined by the number of protons. Atoms A and D both have 79 protons, so they represent the same element.

Answer:

B. A and D represent the same element