The relative number of elements and compounds in a chemical equation are represented by either coefficients, subscripts, charges of phase symbols. I think it's coefficients, but is this right?
My other question is that if you start a reaction with four molecules containing a total of 40 atoms, and the reaction ends with eight molecules how many atoms would there be? I said 20, but I wanted to check this with jiskha since this is my first type of these problems.
I think the intent of question 1 is for the answer to be coefficients.
For question 2, doesn't an equation balance when the number of atoms on the left side equals the number of atoms on the right side? The molecules don't need to balance but the atoms must balance.
Yes, you are correct. The relative number of elements and compounds in a chemical equation are represented by coefficients. Coefficients are whole numbers that are placed in front of the chemical formulas to balance the equation and indicate the ratio of reactants and products.
Regarding your second question, let's break it down step by step.
You start with four molecules containing a total of 40 atoms. Since you haven't specified the specific molecules, let's assume we are talking about a simple compound, such as water (H2O).
Each molecule of water contains 3 atoms (2 hydrogen atoms and 1 oxygen atom). Therefore, four molecules of water would contain a total of 4 * 3 = 12 atoms.
Now, the reaction ends with eight molecules. If we assume the same compound, the number of atoms would still be the same for each molecule (3 atoms).
So, if there are eight molecules, the total number of atoms would be 8 * 3 = 24 atoms.
Therefore, the correct answer is 24 atoms, not 20.