Answer:
or all desendants of a common ancestor
2. A period is a name given to the horizontal row of the periodic table.
3.
a.mg
b.k
c.Fe
d.cu
e.Al
4.
a.Carbon
b.Chlorine
c.Gold
d.strontium
5.
a.period 1
b.period 4
c.period 5
d.period 5
6.
a.group 6
b.group 2
c.group 7
d.group 8 belong ti 1st transitional elements.
7.
a.F
b.Na
c.Ar
d.V
e.I