A compound containg 3 atoms of carbon and 8 atoms of hydrogen is combined in a reaction with oxygen molecules. The two end products of this equation are carbon dioxide (CO2) and water. What element should you look at first in balancing this equation?

C3H8 + O2 ==> CO2 + H2O.

In my mind there is no "first" element to look at in balancing. People balance equations different ways. However, in the spirit of the question, I would start with C.

Oxigeno

To balance the equation, you should first look at the element carbon (C). The goal is to make sure that the number of carbon atoms is the same on both sides of the equation.

Let's break down the information given:
1. The compound contains 3 atoms of carbon and 8 atoms of hydrogen.
2. The products of the reaction are carbon dioxide (CO2) and water.

To balance the equation, you can start by writing the equation:

C3H8 + O2 -> CO2 + H2O

Now, let's count the number of carbon atoms on each side of the equation:
- On the reactant side, we have 3 carbon atoms (C3H8).
- On the product side, we have only 1 carbon atom (CO2).

Since the number of carbon atoms is not the same on both sides, we need to balance it by adding coefficients (the numbers in front of the compounds or elements) to adjust the number of carbon atoms.

Since we have 3 carbon atoms on the reactant side and only 1 on the product side, we can balance the carbon atoms by placing a coefficient of 3 in front of the CO2 compound:

C3H8 + O2 -> 3CO2 + H2O

Now, the equation is balanced with respect to carbon. You can proceed to balance the hydrogen and oxygen atoms.