Question

1. write the formula for magnesium selenide.
2. write the formula for francium nitride.
3. write the formula for aluminum fluoride.
4. write the formula for gallium sulfide.
5. write the formula for thallium antimonide.

compound names

1. write the name for $\ce{caf_{2}}$.
2. write the name for $\ce{mgo}$.
3. write the name for $\ce{ga_{2}s_{3}}$.
4. write the name for $\ce{ca_{3}p_{2}}$.
5. write the name for $\ce{k_{2}s}$.

Explanation:

Question 11:

Step1: Determine ions

Magnesium (Mg) forms $Mg^{2+}$, selenide (Se) forms $Se^{2-}$.

Step2: Balance charges

Charge of Mg²⁺ and Se²⁻: $2+ + 2- = 0$. So ratio 1:1.

Step1: Determine ions

Francium (Fr) forms $Fr^+$, nitride (N) forms $N^{3-}$.

Step2: Balance charges

Let number of Fr⁺ be $x$, N³⁻ be $y$. $x(1+) + y(3-) = 0$ → $x = 3y$. So ratio 3:1.

Step1: Determine ions

Aluminum (Al) forms $Al^{3+}$, fluoride (F) forms $F^-$.

Step2: Balance charges

Let Al³⁺ be $x$, F⁻ be $y$. $3x - y = 0$ → $y = 3x$. Ratio 1:3.

Answer:

$\boldsymbol{MgSe}$

Question 12: