The unknown substance : Lead
<h3>Further explanation</h3>
Given
Density of element
mass of unknown substance = 40 g
volume = 3.5 cm³
Required
The density of unknown substance
Solution
Density is the ratio of mass per unit volume
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:

Input the value to find the density of an unknown substance :
ρ = 40 g : 3.5 cm³
ρ = 11.43 g/cm³
If we look at the table, the substance which has a density of 11.43 is Lead
A solid is an object that has definite shape, volume, and mass. This means that the shape, volume, and mass will never change.
A liquid is something that has definite volume and mass, but it does not have definite shape because a liquid is the shape of its container.
A gas <span>does not have a definite shape, mass, or <span>volume because a gas is able to spread around.</span></span>
The answer is A cause gas clouds hold elements in it