Calculate the electronegativity differences between the following atoms:

1.C-H
2.O-H
3.C-O

Get your electronegativity chart, and calculate. I am certain you can do it.

Do I have to add c and h number together?

The problem you posted says to calculate the electronegativity differences. Differences means you subtract doesn't it.

To calculate the electronegativity difference between two atoms, you need to know the electronegativity values of each atom. Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.

The most commonly used scale for electronegativity is the Pauling scale, which assigns values from 0.7 (for cesium, the least electronegative element) to 4.0 (for fluorine, the most electronegative element).

To calculate the electronegativity difference between two atoms, you subtract the electronegativity of the less electronegative atom from the electronegativity of the more electronegative atom.

1. For C-H:
The electronegativity of carbon (C) is approximately 2.5, and the electronegativity of hydrogen (H) is approximately 2.1.
Electronegativity difference = Electronegativity of C - Electronegativity of H = 2.5 - 2.1 = 0.4

2. For O-H:
The electronegativity of oxygen (O) is approximately 3.5, and the electronegativity of hydrogen (H) is approximately 2.1.
Electronegativity difference = Electronegativity of O - Electronegativity of H = 3.5 - 2.1 = 1.4

3. For C-O:
The electronegativity of carbon (C) is approximately 2.5, and the electronegativity of oxygen (O) is approximately 3.5.
Electronegativity difference = Electronegativity of O - Electronegativity of C = 3.5 - 2.5 = 1.0

Therefore, the calculated electronegativity differences are:
1. C-H = 0.4
2. O-H = 1.4
3. C-O = 1.0