A balloon contains 7.36 g of oxygen gas . How many oxygen molecules
are in the balloon?
The Periodic Table
A. molecules
B. molecules
C. 236 molecules
D. 15 molecules

To find out how many oxygen molecules are in 7.36 g of oxygen gas ( ), we first need to determine the number of moles of oxygen. The molar mass of is approximately 32 g/mol (16 g/mol for each oxygen atom). Thus, the number of moles of in the balloon is .

Now, using Avogadro’s number, which is molecules/mol, we can calculate the number of molecules:

So, the correct answer is B. molecules.

Did you know that oxygen makes up about 21% of the Earth’s atmosphere? That’s a huge amount of oxygen, and it’s vital for life! The oxygen we breathe is produced mainly by plants during photosynthesis, where they absorb carbon dioxide and sunlight to create energy while releasing oxygen. It’s a perfect example of nature’s balance!

On a practical note, if you’re ever trying to calculate the number of molecules in a gas, just remember the steps: find the molar mass, convert grams to moles, and then multiply by Avogadro’s number. It’s a common mistake to forget the conversion to moles, so keep an eye on your units!