Chapter U1.9, Problem 1E

Interpretation Introduction

Interpretation:

The three properties of the elements which are useful in sorting the elements need to be determined.

Concept introduction:

Element can be defined as the basic unit of any substance. It is composed of same type of atoms. All known elements are placed in the long form of periodic table.

In this table all elements are placed in increasing order of the atomic number. Here, atomic number indicates the number of protons in an atom of element.

Answer to Problem 1E

The three properties to classify elements are:

• Atomic number
• Atomic mass
• Metallic and non-metallic nature

Explanation of Solution

In the periodic table, elements are arranged in the increasing order of the atomic number. Atomic number and atomic mass are two unique properties which can be used to classify elements. Here, atomic number is number of protons in an atom and atomic mass is sum of number of protons and neutrons.

The atomic number of an element is unique property and cannot be same for any other element. For example, there is only one element with atomic number 6 and that is carbon atom.

In the periodic table, elemnets are also divided based on their metallic and non-metallic nature. The left side of the periodic table contains all the metallic elements whereas the right side of periodic table contains all the non-metals. Thus, the three properties to classify elements are as follows:

• Atomic number
• Atomic mass
• Metallic and non-metallic nature

Conclusion

The three properties to classify elements are:

• Atomic number
• Atomic mass
• Metallic and non-metallic nature