Chapter 6, Problem 31A

Interpretation Introduction

(a)

Interpretation:

Whether oxygen is a metal, non-metal or a metalloid needs to be determined.

Concept introduction:

Oxygen is an element with atomic number 8 and its chemical symbol is O. It belongs to the p-block and group 16 of the periodic table. Non-metals are those which can accept electron to form anion.

Answer to Problem 31A

Oxygen is a non-metal.

Explanation of Solution

Oxygen belongs to group 16 of the periodic table and it is represented by orange color in the periodic table. Non-metals are represented by orange color in the periodic table. Oxygen can accept two electrons to acquire stable configuration. So, oxygen is a non-metal

(b)

Interpretation Introduction

Interpretation:

Whether barium is a metal, non-metal or a metalloid needs to be determined.

Concept introduction:

Barium belongs to group II of the periodic table, that is, alkaline earth metals. The atomic number of barium is 56 and represented by blue color in the periodic table. The s-block in the periodic table contains 2 groups, group 1 and group 2.

Answer to Problem 31A

Barium is a metal.

Explanation of Solution

The two groups belong to s-block are group I and group II. Group I elements are called as alkali metals. Some elements of group I are Lithium, Sodium etc. Group II elements are called as alkaline earth metals. Some examples of group II elements are magnesium, barium etc. As barium belongs to group II of the periodic table, it is a metal.

(c)

Interpretation Introduction

Interpretation:

Whether germanium is a metal, non-metal or a metalloid needs to be determined.

Concept introduction:

Germanium is an element of the p-block of the periodic table. Its chemical symbol is ‘Ge’ and it is present in group 14 of the periodic table. In the p-block of the periodic table, along with non-metals, metalloid and noble gases are also present.

Answer to Problem 31A

Germanium is a metalloid.

Explanation of Solution

Metalloids are those elements which contain properties of both metal and non-metals. They are present in p-block of the periodic table, that is, from group 13 to 17. Germanium is a metalloid present in group 14 of the periodic table and it contains both the properties of metals and non-metals.

(d)

Interpretation Introduction

Interpretation:

Whether iron is a metal, non-metal or a metalloid needs to be determined.

Concept introduction:

Iron is an element with atomic number 16. The chemical symbol for iron is ‘Fe’. It belongs to d-block of the period table and it is known as transition element.

Answer to Problem 31A

Iron is a metal.

Explanation of Solution

The d-block of the periodic table contains transition elements which are metal. They are called as transition metals because of incomplete d orbitals. Iron is hard, good conductor of heat, sonorous, malleable and ductile. So, it is a metal.