A chemical reaction is the process in which atoms present in the starting substances rearrange to give new chemical combinations present in the substances formed by the reaction. These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.
I found number one
Atoms are not drawn to scale. Molecules of compounds have atoms of two or more different elements. For example, water (H2O) has three atoms, two hydrogen (H) atoms and one oxygen (O) atom. Methane (CH4), a common greenhouse gas, has five atoms, one of carbon (C) and four of hydrogen (H, see Fig.
Answer:
A conversion factor is a variable that transforms the dimension of one variable into the terms of another variable.
Explanation:
Let be 
and 
two variables with diferent dimensions (units), 
is a conversion if transforms the dimension of one variable into the terms of the other variable. That is:
(1)
Where:
- Input, [input unit]
- Output, [output unit]
- Conversion factor, [output unit] per [input unit]
