Question 2.4.1: a. How many protons and electrons are in a Ca^2+ ion? b. Ide......
a. How many protons and electrons are in a Ca^{2+} ion?
b. Identify the ion formed by phosphorus. How many protons and electrons are in this ion?
You are asked to determine the number of protons and electrons in a monoatomic ion.
You are given the identity of the element that forms a monoatomic ion.
a. Calcium is element 20, and the neutral atom has 20 protons and 20 electrons. A Ca^{2+} cation has lost two electrons and has 20 protons and 18 electrons.
b. Phosphorus is in Group 5A and therefore forms an ion with a -3 charge. Phosphorus is element 15 and the P^{3-} ion has 15 protons and 18 electrons.
Is your answer reasonable? A cation (Ca^{2+}) should contain more protons than electrons, while an anion (P^{3-}) has more electrons than protons.