consider the ions mg2+ and br-. how many protons and electrons does each of these ions possess? protons in…

Explanation:

Step1: Recall atomic number concept

The atomic number of an element is equal to the number of protons. The atomic number of Mg is 12 and of Br is 35. So, the number of protons in $Mg^{2 +}$ is 12 and in $Br^-$ is 35.

Step2: Determine electrons in $Mg^{2+}$

A neutral Mg atom has 12 electrons. Since $Mg^{2+}$ has a +2 charge, it has lost 2 electrons. So the number of electrons is $12 - 2=10$.

Step3: Determine electrons in $Br^-$

A neutral Br atom has 35 electrons. Since $Br^-$ has a - 1 charge, it has gained 1 electron. So the number of electrons is $35+1 = 36$.

Answer:

protons in $Mg^{2+}$: 12 electrons in $Mg^{2+}$: 10 protons in $Br^-$: 35 electrons in $Br^-$: 36