Question

If an atom containsg 17 protons and it has one negative charge, how many electrons does the atom contain?

i) 17
ii) 18
iii) 20

Answer 1

ii) 18

Step-by-step explanation:

Atoms consist of positively-charged protons and negatively-charged electrons. Neutral atoms have a charge of 0, and thus contain the same amount of protons and electrons.

Since this atom has one negative charge, the number of electrons must outnumber the number of protons by one. As such, since there are 17 protons, there must be 18 electrons.