Suppose 10 atoms of carbon (C) react with 20 atoms of oxygen (O) to form 10 molecules of carbon dioxide (C*O_{2}) . According to the law of conservation of matter, how many atoms are present in this reaction? (1 point)

Question

30

O 20

O 10

O 15

Answer 1

According to the law of conservation of matter, the number of atoms present before and after the reaction must be the same.

In this reaction, 10 atoms of carbon (C) combine with 20 atoms of oxygen (O) to form 10 molecules of carbon dioxide (C*O_{2}).

In each molecule of carbon dioxide, there is one atom of carbon and two atoms of oxygen. So, in 10 molecules of carbon dioxide, there are 10 atoms of carbon and 20 atoms of oxygen.

Therefore, the total number of atoms in this reaction is 10 atoms of carbon + 20 atoms of oxygen = 30 atoms.

The correct answer is 30.