Question 2 unsaved a neutral atom has an atomic number of 20 and a mass number of 42. How many electrons does the atom have?

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Chemistry

Shaun Bernard

25 December, 11:37

Question 2 unsaved a neutral atom has an atomic number of 20 and a mass number of 42. How many electrons does the atom have?

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Cheeky · Answer 1

Atomic number refers to the number of protons an atom has. Since this atom has 20 protons in the nucleus, the charge of the nucleus is + 20 (neutrons, also in the nucleus, contribute zero charge). Thus, for the atom to be neutral, its electrons must balance the + 20 charge of the nucleus, so it must have 20 electrons.