1. Determine the molar mass of each element:

* Carbon (C): 12.01 g/mol

* Hydrogen (H): 1.01 g/mol

* Oxygen (O): 16.00 g/mol

2. Calculate the molar mass of the entire molecule:

* CH3CH2OH: (2 x 12.01) + (6 x 1.01) + 16.00 = 46.07 g/mol

3. Calculate the mass percentage of each element:

* Carbon (C): [(2 x 12.01) / 46.07] x 100% = 52.14%

* Hydrogen (H): [(6 x 1.01) / 46.07] x 100% = 13.13%

* Oxygen (O): [16.00 / 46.07] x 100% = 34.73%

Therefore, the percent composition of CH3CH2OH is:

* Carbon: 52.14%

* Hydrogen: 13.13%

* Oxygen: 34.73%