# A balloon contains 3.6 x 10^25 helium atoms. How many moles of helium atoms are present?I dont know how to do this question and my chemistry teacher isn't helping me any. Could someone please...

A balloon contains 3.6 x 10^25 helium atoms. How many moles of helium atoms are present?

I dont know how to do this question and my chemistry teacher isn't helping me any. Could someone please explain to me how to found moles in a atom?

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### 3 Answers

A mole is just like saying you have a certain amount of something. When you say you have "ten" of something, it could be cats or atoms or pencils or ducks. You could say you have "ten thousand" of those same items, but instead of using standard notation for the number (10,000) you could use scientific notation, 1 * 10^4, which is exactly the same amount of items. (The numeral 4 tells you how many zeros to place after the 1.) You could be a little more than half a millionaire, and have $600,000, or 6 * 10^5 dollars. To have a mole of something means to have a very large specific number of items, and it's roughly 6 followed by 23 zeros, or 6 * 10^23. To be a bit more precise, a mole is actually 6.02 * 10^23, and all it signifies is how many of something, dogs, oranges, molecules, or atoms you have.

To say a balloon has a mole of helium atoms in it means it contains 6.02 * 10^23 atoms of helium. If a balloon has 3.6 * 10^25 atoms, it means it has more than a mole of atoms (since 25 zeros means its a larger number than 23 zeros.) To find out exactly how many moles, a bit of division is required.

First, take the first part of each number and divide, so 3.6/6.02, which gives you .598. Now take the second part of each number, and in order to perform a division, subtract, so (10^25 - 10^23) which equals 10^2. Put the parts together to get .598 * 10^2. But 10^2 is just 100, so the number could also be read as .598 * 100, or 59.8. So your balloon has 59.8 moles of helium.

As mole represents the number 6.022*10^23

Thus, 1 mole of anything, may it be atoms/molecules/ions etc. corresponds to 6.022*10^23 numbers of it.

The number 6.022*10^23 is also called Avagadro's Number

Nown, number of He atoms present = 3.6*10^25

Thus, moles of He atoms present = number of He atoms/Avagadros' Number

or, moles of He atoms present = (3.6*10^25)/(6.022*10^23)

or, moles of He atoms present = 59.781 moles.

The unit of measurement for atoms and molecules is the mole, and is also the S.I. unit for chemical quantity. A mole of substance contains the same number of atoms in 12g of carbon-12. There are approximately 6x10^23 particles in one mole of substance, and is known as the Avogadro's constant. Since one mole ob substance contains 6x10^23, the number of moles eqals to the division of number of particles by (6x10^23) to get the answer.

Okay, look at the problem. The balloon consists of 3.6x10^25 helium atoms in it and you want to know the number of moles of helium atoms present. Since you know the formula already, the answer is:

**number of moles= number of particles/ 6x10^23**

**= 3.6x10^25/ 6x10^23**

** = 60 mol.**