Question

which of the following does not vary according to rows and periods in the periodic table?
a. electronegativity
b. ionization energy
c. atomic radius
d. radioactivity

Explanation:

• Electronegativity: Increases across a period (left - to - right) and decreases down a group in the periodic table.
• Ionization energy: Generally increases across a period (left - to - right) and decreases down a group.
• Atomic radius: Decreases across a period (left - to - right) and increases down a group.
• Radioactivity: It is a property related to the stability of the nucleus of an atom. It is not directly related to the position of an element in the rows (periods) and columns (groups) of the periodic table in a systematic trend - like the other three properties. Radioactive elements can be found in different periods and groups, and their radioactivity is more about the specific nuclear composition rather than a trend based on periodic table position.

Answer:

D. radioactivity