the symbol p represents the element phosphorus. this elements atomic number is 15. how many protons and…

the symbol p represents the element phosphorus. this elements atomic number is 15. how many protons and electrons are in a p - 3 ion?\n15 protons and 3 electrons\n12 protons and 15 electrons\n15 protons and 18 electrons\n18 protons and 15 electrons
Answer
Explanation:
Step1: Recall proton - atomic number relationship
The atomic number of an element is equal to the number of protons. Phosphorus (P) has an atomic number of 15, so the number of protons in a $P^{- 3}$ ion is 15 since the number of protons does not change during ion - formation.
Step2: Calculate number of electrons in ion
A neutral atom has the same number of electrons as protons. A $P^{-3}$ ion has a charge of - 3, which means it has gained 3 electrons. A neutral P atom has 15 electrons. So the number of electrons in a $P^{-3}$ ion is $15 + 3=18$.
Answer:
15 protons and 18 electrons