Mendeleev arranged the known chemical elements in a table according to increasing
atomic number.
number of electrons.
number of protons.
mass.

one twelth the mass of a carbon-12 atom is used to define a(n)
atomic number.
atomic mass. mass number.
atomic mass unit.

a member of the boron family has three valence electrons, while a member of the nitrogen family has
none.
five.
four.
three.

what is the formula for the ionic compound lithium oxide?
lio
li2o
lio2
li2o3

water has a higher boiling point than expected because
there is so much water vapor in the atmosphere.
water molecules are not very massive.
hydrogen and oxygen form single covalent bonds.
of the strong attractions between polar water molecules.