Periodic Trends

[Hannah Padilla 1H]

I know that for Ionization energy, electronegativity, and electron affinity the trend is that it increases towards the upper right corner (He). However, how would you determine which atom is more electronegative if there are diagonal (like Na and Ca)

[Kevin ODonnell 2B]

A TA told me that going up a column (group) means it is more electronegative than just going across a row. So in this case Na would be more electronegative than Ca. I would still ask a TA for a further explanation on why this occurs though.

[Kobe_Wright]

The above comment is wrong, Ca is actually more electronegative. Electronegativity increases as you go up a group and across a row because the farther up a group the less protons which means less pull to the nucleus and across the row means more valence electrons which increases the negative charge, but you need to check a chart of electronegativities to be sure for some elements.

[Madelyn Romberg 1H]

When it comes to diagonal elements, it is generally difficult to [censored] their comparing electronegativity because you experience two opposing forces that influence electronegativity. In the case of sodium and calcium, sodium appears to have a higher electronegativity because it is in the period above calcium. However, calcium is also further into the period (a higher group) which increases the electronegativity. Therefore, with elements close together in a diagonal form, it is difficult to tell unless you are given their actual values.