Answers to exam prep questions - Chemistry

How many electrons does an aluminum ion Al3+, have compared to an aluminum atom?

An aluminum atom looses its 3 outer electrons and becomes a positive ion with a charge of +3, so an aluminum ion has 10 electrons. A normal aluminum atom has 13 electrons.

How many electrons does an oxide ion, O2-, have compared to an oxygen atom?

An oxide ion gains 2 electrons, which gives an oxide ion a total of 10 electrons. A normal oxygen atom has 8 electrons.

How many extra electrons does an oxide ion have compared to an oxygen atom

An oxide ion has a charge of -2 which means that the ion has gained 2 extra outer electrons. This happens to fill up an oxide ions outer shells up to 8. A normal oxygen atom has 6 outer electrons.

why do non metals gain electrons?

Because its easy for non metals to gain electrons due to heir high electronegativity.

Why do metals loose electrons?

Because they find it easier to loose electrons due to their low electronegativity

Whats the word equation for the reaction between lithium and water?

Lithium + water --> lithium hydroxide + hydrogen

What's electronegativity?

The measure of how frequent atoms attract a bonding pair of electrons to itself

What are intermolecular forces?

forces of attraction between molecules

What's a diatomic molecule?

molecules composed of only two atoms, of the same or different chemical elements.

The word equation for sodium and oxygen

sodium + oxygen -> sodium oxide

The word equation for the displacement between chlorine and sodium iodine

sodium iodide + chlorine -> sodium chloride + iodine