Question

According to the law of conservation of matter, the number of ________ is not changed by a chemical reaction.

Answer 1

mass

Answer 2

Moles

Answer 3

I personaly would say atoms for this one

Answer 4

The number of moles does not change.

Answer 5

alright lets think about this. What is a mole? oh that would be 6.022x10^22 atoms. So by saying that a chemical reaction wont change that number of moles during a reaction what are you really saying?

Answer 6

I guess I better clear this up before someone else corrects me a mole is a large unit number. You can have a mole of anything i.e a mole of atoms, molecules, or even cars. The mole is to a chemist like a dozen is to a baker, It is a way for us to change numbers that would be impossible to wrk with and make them easy to work with.

Answer 7

I think @zbay is right...moles could refer to moles of molecules, atoms particles, etc. If the moles of ----- in the reactants is of molecules and the moles in the products is measured in atoms, it would be different. So the number of atoms DEFINITELY does not change..

Answer 8

actually it is mass...when you come across nuclear reactions you find that the conservation of atoms doesn't hold...but in chemistry in general conservation of atoms is a justified approximation as @zbay said..

Answer 9

the number of moles can change in a reaction; for an example
In the Harber process 4 moles of gas become 2 moles of gas
\[3{H_2}_{(g)} + {N_2}_{(g)} \rightarrow 2{NH_3}_{(g)}\]

Answer 10

its the number of atoms changed. came from study island. Moles was wrong