Forming covalent bonds | Exit Quiz | Oak National Academy

What is a covalent bond?

• A bond between two metal atoms.

• A bond between a metal and a non-metal atom.

• A bond where two non-metal atoms share a pair of electrons.

• A bond formed of ions, where atoms have transferred electrons.

Answer explanation

A covalent bond is a bond where two non-metal atoms share a pair of electrons. This sharing allows each atom to achieve a full outer shell of electrons.

How many covalent bonds will an atom form if it needs three electrons to complete its outer shell?

• 1

• 2

• 3

• 4

• Not enough information is known

Answer explanation

An atom that needs three electrons to complete its outer shell will form three covalent bonds, sharing a total of three pairs of electrons with one, two or three atoms.

What does a displayed formula of a covalent substance show?

• All of the atoms present in the substance.

• All of the bonds between atoms.

• A shorthand version of the structure, showing only some of the atoms.

• A shorthand version of the structure, showing only some of the bonds.

• Each line drawn represents a shared pair of electrons.

Answer explanation

A displayed formula shows all atoms and bonds in a covalent substance, using lines to represent shared pairs of electrons. It is a 2D model of the molecule.

What is the purpose of a dot and cross diagram?

• To show the physical state of a substance.

• To show how chemical bonds are formed between atoms.

• To represent the empirical formula of a compound.

• To show the arrangement of metal ions.

Answer explanation

A dot and cross diagram is used to show how chemical bonds are formed between atoms, with dots and crosses representing electrons from each atom.

A ___ is a particle consisting of a fixed number of non-metal atoms covalently bonded together.

Answer explanation

A molecule is a particle consisting of a fixed number of non-metal atoms covalently bonded together. It is not a single atom or a charged particle.

Atoms can share multiple pairs of electrons to achieve full outer shells, leading to double or ___ covalent bonds.

Answer explanation

Atoms can share multiple pairs of electrons to achieve full outer shells, leading to double or triple covalent bonds. This allows them to attain a stable electron configuration.