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

Question

A. 15
B. 20
C. 30
D. 10

Answer 1

To solve the problem, we need to count the total number of atoms before and after the reaction.

Given:

• Carbon (C) atoms: 10
• Oxygen (O) atoms: 20

In the chemical reaction, they combine to form carbon dioxide (CO2):

• Each CO2 molecule consists of 1 carbon atom and 2 oxygen atoms.
• Therefore, 10 CO2 molecules will contain:
  • 10 carbon atoms (10 x 1 C)
  • 20 oxygen atoms (10 x 2 O)

Now we can tally the total number of atoms involved in the reaction:

1. Before the reaction:

   • 10 carbon atoms + 20 oxygen atoms = 30 atoms

2. After the reaction:

   • 10 CO2 molecules contains 10 carbon atoms and 20 oxygen atoms = 30 atoms

So, according to the law of conservation of matter, the total number of atoms remains the same before and after the reaction.

Therefore, the total number of atoms present in this reaction is:

C. 30