Final answer:
To calculate electronegativity difference, subtract the electronegativity value of one atom from another. It is not related to atomic numbers, atomic masses, ionization energies, or electron affinities, but based on a dimensionless scale showing an atom's ability to attract electrons in a bond.
Step-by-step explanation:
To calculate the electronegativity difference between atom pairs, you use the known electronegativities of the atoms. The electronegativity value indicates how strongly an atom can attract electrons in a bond. It's a dimensionless number typically found on a chart in chemistry textbooks or online resources. You calculate the difference by subtracting the electronegativity of one atom from that of the other in the bond.
For example, in a carbon-hydrogen (C-H) bond, if the electronegativity of carbon (C) is 2.5 and that of hydrogen (H) is 2.1, the difference is calculated as 2.5 - 2.1 = 0.4. A larger electronegativity difference usually indicates a more polar covalent bond.
Also, it's important to distinguish between electron affinity and electronegativity. While electron affinity refers to the measurable energy change when an atom gains an electron in the gas phase, electronegativity is a calculated value showing how tightly an atom attracts electrons when forming a bond. Electronegativities are assigned on a scale developed by Linus Pauling, generally ranging from 0 to 4.