# Question #4a230

##### 1 Answer

You have

#### Explanation:

To figure out how many atoms of copper you get in **1 gram** of copper, you need to use copper's molar mass.

An element's molar mass tells you what the mass of **one mole** of that element is.

Now, one mole of an element is defined as **Avogadro's number**. This means that if you know what the mass of one mole is, you can calculate how many atoms would fit into a single gram by using Avogadro's number.

In copper's case, you know that its molar mass is **63.546 g/mol**.

This tells you that

#1color(red)(cancel(color(black)("g"))) * (6.022 * 10^(23)"atoms of Cu")/(63.546color(red)(cancel(color(black)("g")))) = color(green)(9.5 * 10^(21)"atoms of Cu")#

I'll leave the answer rounded to two sig figs, despite the fact that you only gave one sig fig for the mass of the copper sample.