6.5 Molecular Compounds: Sharing Electrons

What is a molecular compound?

A molecular compound consists of atoms of two or more nonmetals that share one or more valence electrons, forming covalent bonds.

How are the atoms in a molecular compound held together?

The atoms are held together by covalent bonds that form a molecule.

Give two examples of molecular compounds.

Water (H2O) and carbon dioxide (CO2).

What is the basic structure of a molecule of water?

A molecule of water (H2O) consists of two atoms of hydrogen and one atom of oxygen.

How is the first nonmetal in the formula of a molecular compound named?

The first nonmetal is named by its element name.

How is the second nonmetal in the formula of a molecular compound named?

The second nonmetal is named using the first syllable of its element name, followed by "ide."

What prefixes are used to indicate the number of atoms in a molecular compound?

Mono, di, tri, tetra, penta, hexa, hepta, octa, nona, and deca.

Why are prefixes necessary in naming molecular compounds?

Prefixes indicate the number of atoms of each element in the compound because several different compounds can be formed from the same two nonmetals.

How is the compound CO named?

Carbon stays as carbon, while oxygen becomes ‘monoxide’ because there’s 1 oxygen atom

What happens when the vowels o and o or a and o appear together in prefixes?

The first vowel is omitted.

How are molecular compounds named?

the names of two nonmetals are given along with prefixes for the number of atoms of each. To write the formula from the name, we use the symbol for each element and a subscript if a prefix indicates two or more atoms.

What is the general naming rule for compounds having two elements?

State the first element name followed by the name of the second element with an "ide" ending.

How can you tell if a compound is ionic or molecular based on its first element?

If the first element is a metal, the compound is usually ionic; if the first element is a nonmetal, the compound is usually molecular.

When is a Roman numeral used in naming ionic compounds?

A Roman numeral is used if the metal can form more than one type of positive ion

How are ionic compounds with three or more elements named?

They are named by ionic rules but have an "ate" or "ite" ending when the polyatomic ion has a negative charge.

How do you write the formula from the name of a molecular compound?

Use the symbol for each element and add a subscript if a prefix indicates two or more atoms.

What is the formula for carbon dioxide based on its name?

CO2.

How is the compound NO named? Think about when vowels like a or o appear together

Nitrogen oxide (prefix "mono" is usually omitted when vowels are together in molecular compounds).