We’re being asked to determine what must be the same before and after a chemical reaction.
Recall that Law of Conservation of Mass: that mass is neither created nor destroyed in chemical reactions.
Which of the following must be the same before and after a chemical reaction?
A: The sum of the masses of all substances involved.
B: The number of molecules of all substances involved.
C: The number of atoms of the type involved.
D. both (a) and (c) must be the same.
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What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Balancing Chemical Equations concept. You can view video lessons to learn Balancing Chemical Equations. Or if you need more Balancing Chemical Equations practice, you can also practice Balancing Chemical Equations practice problems.