Question

Some physical properties of elements in a group of the periodic table are described below.

Poor conductor of electricity
Poor conductor of thermal energy
Atoms contain seven valence electrons
Brittle in the solid state
Low melting points and boiling points
The elements described above belong to which group?

A
Alkaline earth metals
B
Noble gases
C
Alkali metals
D
Halogens

Answer 1

The physical properties described correspond to the elements in group D, which are the Halogens. Halogens are known to be poor conductors of electricity and thermal energy, and they are brittle in the solid state. They have seven valence electrons and typically have low melting points and boiling points compared to metals.