Simple Molecules Flashcards

All 4 cards in this deck

What is the typical size (order of magnitude) of an atom or a small molecule?

About $1 \times 10^{-10}$ m.

What are the steps to draw a dot and cross diagram of a simple molecule (outer shell electrons only)?

e.g. water, $\mathrm{H_2O}$

1. Draw the outer-shell electrons of each atom: O has 6, each H has 1.

2. Overlap each outer shell to make a shared pair in each overlap: 2 shared pairs (one O–H bond each).

3. Show the atom's remaining outer electrons: 4 electrons left on the O only.

How many electrons are shared in a double bond?

e.g. the O=O bond in an oxygen molecule

4 electrons — two shared pairs.

In the formula of a molecule, what does the small number written after an element's symbol tell you?

e.g. the 2 in $\mathrm{H_2O}$

How many atoms of that element are in one molecule.

e.g. one molecule of $\mathrm{H_2O}$ contains 2 hydrogen atoms (and 1 oxygen atom).