The periodic system: periods and groups
Answers are for parents and teachers.
1
How many elements are in period 2?
8
2
How many elements are there in periods 4 and 5 together?
36
3
In which group are Be and Mg? Formulas of their highest oxides?
Main subgroup of Group II; BeO and MgO.
4
How does metallic character change in the series Li, Na, K and why?
It increases from Li to K because the atomic radius grows and the outer electron is further from the nucleus.
5
Name the elements of the main subgroup of Group VII.
F, Cl, Br, I, At (halogens).