Ions Flashcards

All 6 cards in this deck

What is an ion?

An atom or group of atoms with a positive or negative charge.

What is a cation and what is an anion?

A cation is a positive ion (an atom that has lost electrons); an anion is a negative ion (an atom that has gained electrons).

What charge do the ions of elements in groups 1, 2, 6 and 7 have?

Group 1: $1+$, group 2: $2+$, group 6: $2-$, group 7: $1-$.

A chlorine atom has the electronic configuration 2.8.7. What is the electronic configuration of the chloride ion, $\mathrm{Cl^-}$?

2.8.8 — it has gained one electron, giving a full outer shell.

What are the steps to find the numbers of protons, neutrons and electrons in a simple ion?

e.g. a fluoride ion $\mathrm{F^-}$, atomic number 9, mass number 19

1. Protons = atomic number = 9
2. Neutrons = mass number − atomic number = 19 − 9 = 10
3. Electrons = protons + 1 for each negative charge (− 1 for each positive charge) = 9 + 1 = 10

True or false? When an atom forms an ion, its number of protons changes.

False. Only electrons are lost or gained; the number of protons (and the mass number) stays the same.