Question

Which of these would BEST describe the structural difference between magnesium and aluminum?

Answer 1

Hello.

The answer is:  B) Magnesium has one less proton than aluminum.

Magnesium atomic number is 12 while Aluminium's is 13. This means 1 more proton and weights more than magnesium since proton and neutrons contribute to the weights of the atoms.  

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Answer 2

B) Magnesium has one less proton than aluminum. The number of protons is shown in the left corner. Magnesium has 12 and aluminum has 13.