covalent bonding in water, ammonia and methane

examples molecules containing several atoms

• water

• ammonia

• methane

what does the formula for water (H₂O) tell us?

that a water molecule contains two atoms of hydrogen and one atom of oxygen.

oxygen has 8 electrons how many electrons are in the first energy level?

two electrons

how many electrons are there in the outer energy level?

six electrons

both hydrogen atoms require how many electrons to achieve a full outer energy level?

one electron

how many electrons does the oxygen atom require?

two more electrons

how can we achieve this?

by overlapping the outer energy levels for the hydrogen atoms and oxygen atoms.

by sharing electrons what do both the hydrogen atoms and oxygen atoms have?

a full outer energy level

what is shared pair of electrons?

a covalent bond

how many covalent bonds does the water molecule contain?

two covalent bonds

dot and cross diagram and stick diagram for water molecule

ammonia has a formula NH3 what does this tell us?

this tells us that an ammonia molecule contains one atom of nitrogen and three atoms of hydrogen.

how many electrons does nitrogen have in its outer energy level?

five electrons

energy level diagram for ammonia

how many covalent bonds does a molecule of ammonia have?

three covalent bonds

by sharing electrons the nitrogen atom and the hydrogen atoms have each achieved what?

a full outer energy level

dot and cross and stick diagram for ammonia

methane has a formula CH4 what does this tell us?

that a methane molecule contains one atom of carbon and four atoms of hydrogen.

how many electrons does carbon have in its outer energy level?

four electrons

energy level diagram for methane (covalent bonding in methane molecule)

how many covalent bonds does a molecule of methane have?

four covalent bonds

what do the hydrogen atoms and carbon atom now have?

full outer energy levels

dot and cross diagram and stick diagram for methane