Chapter 12, Problem 111QGW

Interpretation Introduction

Interpretation: Verify the atomic weight of the middle element in a triad is approximately the average of two. Along with this, explain the trend of melting points of hydrogen containing compounds like $HCl,HBr\text{}andHI$.

Concept Introduction:

Atomic weight of an element is defined as the average of atomic masses of different isotopes of that element.

Triad is a group of three elements, where the atomic weight of one of the element is the mean of the other two.

A solid consists of particles that possess high intermolecular forces of attraction. On absorption of heat, these forces tend to become weak and the attraction between molecules decreases. This led to the conversion of solid into liquid and the process is called as melting.