PRACTICE: Determine the number of protons, neutrons and electrons in the following atoms.

How many electrons does an atom of each of the following elements need to lose to achieve a noble gas configuration? By losing that many electrons, which noble gas configuration is achieved?

(d) Potassium

How many electrons does an atom of each of the following elements need to gain to achieve a noble gas configuration? By gaining that many electrons, which noble gas configuration is achieved?

(b) Iodine

Why is argon considered to be so stable that it is referred to as a noble gas?

PRACTICE: Determine the number of protons, neutrons and electrons in the following atoms.

PRACTICE: Determine which of the three principles of electron configuration is being broken in the electron diagrams below.

PRACTICE: Determine which of the three principles of electron configuration is being broken in the electron diagrams below.

Nitrogen has relatively stable isotopes (half-life greater than 1 second) of mass ­numbers 13, 14, 15, 16, and 17. All except ¹⁴N and ¹⁵N are radioactive.) Calculate how many protons and neutrons are in each of these isotopes of nitrogen.