Question

The below table compares the number of electrons in two neutral atoms.AtomNumber of ElectronsNe10Na11Compare the electron configuration and atomic radius of these two atoms and use that to explain the difference in their reactivity.

Answer 1

Atom

Number of Electrons

Ne10

Na11

Those are Ne and Na electron configuration

Now Atomic radius:

For Ne: 38 pm

For Na: 190 pm

The reactivity of Na is higher than Ne because Ne has the last orbital complete. Na has only one electron in the last orbital.

We can also say that the reactivity of metals increases further to the left in the period (fewer electrons to remove).

The reactivity of metals increases as they move up a group (greater tendency to lose electrons).

Noble gases, which, although they belong to the main elements because they are very stable due to the fact that they have their last orbital full (i.e., they have eight electrons in their valence shell), are not very reactive.