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?
a. 20
b. 30
c. 10
d. 15
The correct answer would be b. 30.
According to the law of conservation of matter, the total number of atoms before a chemical reaction must be equal to the total number of atoms after the reaction.
In this case, there are 10 atoms of carbon and 20 atoms of oxygen before the reaction. Since each carbon dioxide molecule contains 1 carbon atom and 2 oxygen atoms, the 10 molecules of carbon dioxide would contain 10 carbon atoms and 20 oxygen atoms.
Therefore, the total number of atoms after the reaction would be 10 carbon atoms + 20 oxygen atoms = 30 atoms.