Question

A group of elements in the periodic table is given below (Boron is the first member of the group and thallium is the last.)

Boron, Aluminium, Gallium, Indium, Thallium

Answer the following questions in relation to the above group of elements:

1. Which element has the most metallic character?
2. Which element would be expected to have the highest electronegativity?
3. If the electronic configuration of aluminium is 2, 8, 3, how many electrons will be there in the outermost shell of thallium?
4. The atomic number of boron is 5. Write the chemical formula of the compound formed when boron reacts with chlorine.
5. Will the elements in the group to the right of this boron group be more metallic or less metallic in character? Justify your answer.

Answer 1

1. Thallium
2. Boron
3. Thallium
4. BCl₃
5. The elements to the right are less metallic because metallic character drops across a row.