Suppose 10 atoms of carbon react with 20 atoms of oxygen to form 10 molecules of carbon dioxide. According to the law of conservation of matter how many atoms are present in this reaction

Answer 1

According to the law of conservation of matter, the number of atoms must remain the same before and after a chemical reaction.

In your reaction:

• You start with 10 carbon (C) atoms.
• And you have 20 oxygen (O) atoms.

So, the total number of atoms before the reaction is: \[ 10 \text{ (C atoms)} + 20 \text{ (O atoms)} = 30 \text{ atoms} \]

After the reaction, you form 10 molecules of carbon dioxide (CO₂). Each molecule of CO₂ contains 1 carbon atom and 2 oxygen atoms. Therefore, for 10 molecules of CO₂, you have:

• 10 carbon atoms (from 10 CO₂ molecules)
• \(10 \times 2 = 20\) oxygen atoms (from 10 CO₂ molecules)

So, the total number of atoms after the reaction is: \[ 10 \text{ (C atoms)} + 20 \text{ (O atoms)} = 30 \text{ atoms} \]

Thus, the total number of atoms present in this reaction, both before and after, is 30.