Question

question 9 of 32
how many electrons are in an ion of calcium (ca2+)?
the periodic table
a. 18
b. 22
c. 2
d. 0

Explanation:

Step1: Find calcium's atomic number

Calcium (Ca) has atomic number 20, which means neutral Ca has 20 electrons.

Step2: Analyze the ion charge

The $Ca^{2 + }$ ion has a +2 charge, meaning it has lost 2 electrons.

Step3: Calculate number of electrons

$20 - 2=18$

Answer:

A. 18