Chapter 4:Molecular compounds

Molecular shapes

Molecular shapes

________ can be predicted by noting how many bonds and electron pairs surround individual atoms and applying the valence- shell electron- pair repulsion (VSEPR) model.

Fluorine

________ is the most electronegative element.

binary compound

When two different elements combine, they form a(n) ________.

covalent bond

The bond formed when atoms share electrons is called a(n) ________, and the group of atoms held together by ________ is called a molecule.

Molecules

________ can be polar if electrons are attracted more strongly to one part of the ________ than to another.

Structural formulas

________, use lines to show how atoms are connected, and Lewis structures, show both the connections among atoms and the placement of unshared valence electrons.

nuclei of atoms

The electrons act as a kind of "glue "to bind the two ________ together into a molecule.

electronegativity

The ability of an atom to attract electrons in a covalent bond.

covalent bonds

Although metals and reactive non- metals can achieve an electron octet by gaining or losing an appropriate number of electrons to form ions, non- metals can also achieve an electron octet by sharing an appropriate number of electrons in ________.

STEP 1

Find the total number of valence electrons of all atoms in the molecule or ion

STEP 2

Draw a line between each pair of connected atoms to represent the two electrons in a covalent bond

STEP 3

Using the remaining electrons, add lone pairs so that each atom connected to the central atom (except H) gets an octet

STEP 4

Place any remaining electrons in lone pairs on the central atom

STEP 5

If the central atom does not yet have an octet after all electrons have been assigned, take a lone pair from a neighbouring atom and form a multiple bond to the central atom

STEP 1

Draw a Lewis structure of the molecule, and identify the atom whose geometry is of interest

STEP 2

Count the number of electron charge clouds surrounding the atom of interest

STEP 3

Predict molecular shape by assuming that the charge clouds orient in space so that they are as far away from one another as possible

STEP 1

Name the first element in the formula, using a prefix if needed to indicate the number of atoms

STEP 2

Name the second element in the formula, and modify by adding the -ide suffix as when naming anions

bond length

optimum distance between nuclei.

molecular formula

formulas that show the number of atoms and type on atoms in one molecule of the compound.

binary compound

When two different elements combine, they form a binary compound.