Electronegativity down group 2
Learning outcomes
After studying this page, you should be able to:
- describe and explain the trend in electronegativity down group 2.
Electronegativity
The table shows electronegativity values for the common elements in group 2.
| Element | Symbol | Atomic number | Electronegativity |
|---|---|---|---|
| Beryllium | Be | 4 | 1.57 |
| Magnesium | Mg | 12 | 1.31 |
| Calcium | Ca | 20 | 1.00 |
| Strontium | Sr | 38 | 0.95 |
| Barium | Ba | 56 | 0.89 |
Electronegativity is the ability of an atom to attract the bonding electrons in a covalent bond.
The table gives values on the Pauling scale, which has no units. Fluorine (3.98) is the most electronegative element.
Description
The graph shows how electronegativity varies down group 2:
- as you go down group 2, electronegativity decreases.
When you click on the download symbol, you will be able to download the graph as an image file or pdf file, save its data, annotate it, and print it.
Explanation
Going down group 2:
- the atomic radius increases …
- the outer electrons are more shielded from the attraction of the nucleus …
- so electrons will be less strongly attracted to the nucleus.
You might expect electronegativity to increase going down the group because the nuclear charge increases. This does not happen, because the factors described here have a greater influence on the electronegativity.
