In Ca₃(PO₄)_x, the value of x is:

1. 1
2. 2
3. 3
4. 4

2

Reason — Chemical formula of calcium phosphate:

$\text{Ca}^{2+} \space \text{PO}$4^{3-} \\[1em] \overset{\phantom{22}{2}}{\text{Ca}} \space {\swarrow}\mathllap{\searrow} \space \overset{3}{\text{PO}4} \Rightarrow \underset{\phantom{2}{3}}{\text{Ca}} \space {\swarrow}\mathllap{\searrow} \underset{\phantom{2}{2}}{\text{PO}4} \\[1em] \text{Ca}3\text{(PO}4)2

∴ Chemical formula of calcium phosphate is Ca₃(PO₄)₂ hence x = 2.