Answer:
Option C is correct : Calcium and magnesium are alkaline earth metals.
Explanation:
From the given option C is correct.
Calcium and magnesium are alkaline earth metals. Both are present in group 2. Each have 2 valence electrons.
All other options are incorrect, because:
a) Chlorine and iodine are alkali metals.
Chlorine and iodine are not alkali metals. These are halogens. Both have seven valence electrons and form salt with alkali metals.
B) Potassium and phosphorus are in the same group.
Potassium and phosphorus are not present in same groups. Potassium is present in group 1 and phosphorus is present in group 15.
d) Boron and silicon are present in same period.
Boron and silicon are not present in same period. Boron is present in period 2 while silicon is present in period 3.
e) Lead and tin both are non metals.
This option is also incorrect because lead and tin both are metals.
Thus, only option C is correct.
