In a chemical reaction, reactants interact to form products. This process is summarized by a chemical equation. In the Balancing Chemical Equations Gizmo, look at the floating molecules below the initial reaction: H2 + O2 H2O. 1. How many atoms are in a hydrogen molecule (H2)? 2. How many atoms are in an oxygen molecule (O2)? 3. How many hydrogen and oxygen atoms are in a water molecule (H2O)? 4. In general, what does a subscript (such as the "2" in H2) tell you about the molecule? 5. A chemical equation is balanced if the number of each type of atom on the left side is equal to the number of each type on the right side. Is this reaction balanced?

See answer below

Explanation:

Let's write the equation again:

H₂ + O₂ > H₂O

Now that we have written the equation, let's solve the exercise:

1. In this case, we first need to make a difference between atom and molecule. An atom is just a single element, a molecule it's when you have more than 1 element in a compound.

Knowing this, we have the H₂. In this case we only have one element, Hydrogen. However, as you can see in the expression, we have a number 2 as a subscript. The number 2 means that the hydrogen it's not alone, we do not have one hydrogen, we have two hydrogens, therefore, it becomes a molecule. Now, This molecule, according to the number 2 as subscript, means that the molecule of hydrogen have 2 atoms of hydrogens, and this formed the molecule, therefore, there are 2 atoms of hydrogens in H₂.

2. Following the same explanation of above, but using oxygen, we have the same thing, so, in a molecule of O₂, we have 2 atoms of oxygen.

3. The molecule of water is composed of Hydrogen and oxygen. As you can see, in this case we have 2 hydrogen and 1 oxygen, therefore, in 1 molecule of water, there are 1 atom of oxygen and 2 atoms of hydrogen.

4. The subscript, as you may know now, tell us the number of atoms that you have in a molecule or compound. This number also means, in different compounds the oxidation state of the atoms that conform the molecule.

5. No, the equation is not balanced, because we do not have the same number of oxygen on the side of the products. We need to balance that. As the oxygen is unbalanced, we just need to put numbers as coefficients, behind the molecule. This number will multiply the number of atoms of the referred molecule. So, doing this with the water on the products to equal the number of oxygen, we have:

H₂ + O₂ > 2H₂O

But this 2, unbalance at the same time the number of hydrogens. We now have 4 hydrogens in the product, so, to balance this, we put a 2 on the reactants:

2H₂ + O₂ > 2H₂O

Now the reaction is balanced.

Hope this helps

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )