Determine the electron configuration of Mg and Mg2+, and the valency of ClO and Cl- in Ca(ClO)2, and the electron configuration of Cl-.

here are the solutions for questions 10 and 11.

10. a)
Magnesium (Mg) has an atomic number (Z) of 12, meaning it has 12 electrons.
The s, p configuration for a neutral Magnesium atom is:

$$\boxed{\text{1s}^2 \text{2s}^2 \text{2p}^6 \text{3s}^2}$$

10. b)
When Magnesium becomes an ion $\text{Mg}^{2+}$, it loses two electrons from its outermost shell.
The sub-shell that is emptied is the $\boxed{\text{3s sub-shell}}$.

10. c)
After losing the two electrons from the 3s sub-shell, the resulting configuration of the $\text{Mg}^{2+}$ ion is:

$$\boxed{\text{1s}^2 \text{2s}^2 \text{2p}^6}$$

11. a)
In Calcium Hypochlorite ($\text{Ca(ClO)}_2$), Calcium (Ca) is in Group 2 and has a valency of +2.
Since there are two hypochlorite radicals ($\text{ClO}$) for every one calcium ion, each $\text{ClO}$ radical must have a valency of -1 to balance the charge.
The valency of the Hypochlorite radical (ClO) is $\boxed{\text{-1}}$.

11. b) (i)
Chlorine (Cl) has an atomic number (Z) of 17, meaning a neutral atom has 17 electrons. Its configuration is $1s^2 2s^2 2p^6 3s^2 3p^5$.
A $\text{Cl}^-$ ion gains one electron to achieve a stable octet. This electron fills the 3p sub-shell.
The s, p configuration for the $\text{Cl}^-$ ion is:

$$\boxed{\text{1s}^2 \text{2s}^2 \text{2p}^6 \text{3s}^2 \text{3p}^6}$$

11. b) (ii)
Calcium (Ca) reacts with Chlorine gas ($\text{Cl}_2$) to form Calcium Chloride ($\text{CaCl}_2$).