Law of Conservation of Matter Quick Check

Question

1 of 41 of 4 Items
Question
Suppose 10 atoms of carbon (C) react with 20 atoms of oxygen (O) to form 10 molecules of carbon dioxide (CO2
). According to the law of conservation of matter, how many atoms are present in this reaction?(1 point)
Responses

15
15

10
10

30
30

20

Answer 1

According to the law of conservation of matter, the total number of atoms in a chemical reaction must remain constant.

In this case:

• Reactants: 10 carbon atoms + 20 oxygen atoms = 30 total atoms
• Products: 10 molecules of carbon dioxide (CO2) contain 10 carbon atoms and 20 oxygen atoms (since each CO2 molecule has 1 carbon and 2 oxygen atoms):
  • 10 carbon atoms + (10 molecules × 2 oxygen atoms per molecule = 20 oxygen atoms) = 30 total atoms

So, the total number of atoms present in this reaction is 30.

The correct response is 30.