Properties of materials

Medium

The table below shows the physical properties of four different substances: $W\mathbf{W}$ , $X\mathbf{X}$ , $Y\mathbf{Y}$ , and $Z\mathbf{Z}$ .

Substance	Melting point ( $∘C^\circ\text{C}$ )	Boiling point ( $∘C^\circ\text{C}$ )	Soluble in water?	Conducts electricity in solid state?	Conducts electricity in molten state?
$W\mathbf{W}$	$- 114$	$78$	Yes	No	No
$X\mathbf{X}$	$801$	$1413$	Yes	No	Yes
$Y\mathbf{Y}$	$1538$	$2862$	No	Yes	Yes
$Z\mathbf{Z}$	$- 189$	$- 186$	No	No	No

Identify which substance is a liquid at room temperature ( $20∘C20^\circ\text{C}$ ).

[1]

Substance $X\mathbf{X}$ is an ionic compound. Use the data in the table to explain why.

[3]

Properties of materials Questions