Question Text
Question 9 :
How many moles are present in $6.023\times 10^{22}$ molecules of $CO_2$?<br>
Question 13 :
What is the name given to a pure substance with only one kind of atoms?
Question 17 :
The prefix used for denoting an order of magnitude of ${ 10 }^{ 6 }$ is:<br/>
Question 19 :
A sample of ammonia has a mass of $51.1g$. How many molecules are in this sample?
