# What is the density of a substance that has a mass of 2.7 g and a volume of 35 mL?

##### 1 Answer

#### Explanation:

As you know, density is defined as mass **per unit of volume**.

That means that every time you're asked to find the density of a substance, you have to determine the mass of *one unit of volume* of that substance.

In this case, the volume is given to you in *milliliters*,

So, how would you go about finding the mass of

Density is essentially a measure of how well the atoms of a given substance *pack* per unit of volume.

The important thing to realize about density is that **every** unit of volume will pack the same number of atoms, i.e. will have **the same mass**.

This means that you can use the fact that a volume of **per milliliter**

#1 color(red)(cancel(color(black)("mL"))) * "2.7 g"/(35 color(red)(cancel(color(black)("mL")))) = "0.077 g"#

So, if

#rho = color(green)("0.077 g/mL")#