Covalent Chemistry Edrolo Chapter 2

The valence of an atom is their....

• inner shell

• outer shell

According to the octet rule, atoms are most stable with how many electrons in their valence shell?

• Two

• Four

• Six

• Eight

Which element is the most electronegative?

• Fluorine

• Oxygen

• Fluoride

• Nitrogen

• Chlorine

A difference in electronegativity between two covalently bonded atoms results in...

• a non-polar covalent bond

• a non-polar hydroge bond

• a polar dispersion bond

• a polar covalent bond

True or False: a molecule with polar covalent bonds must be polar overall

• True

• False

Of the molecules CO₂, CH₄, NH₃, H₂O, BF₃, and H₂S the two with the same shape are: 

• CO₂ and H₂O,

• H₂O and H₂S

• CH₄ and NH₃

• BF₃ and NH₃

Of the intramolecular forces shown below, which is the most polar?

• C-H

• N-H

• O-H

•     F-H

Select the alternative that correctly lists the properties of molecular compounds.

• Low melting point, ductile and conducting electricity as a liquid

• Low melting point, lattice structure and brittle

• High melting point, non-conductive of electricity and hard

• Low melting point, non-conductive of electricity as a solid and as a liquid

A single covalent bond is formed when:

• two atoms share a pair of electrons

• one atom donates an electron to another atom

The melting point of a substance is the temperature at which

• the substances changes from a liquid to a soild

• the substances changes from a gas to a liquid

• the substances changes from a soild to a liquid

• the substances changes from a liquid to a gas