Chapter 2, Problem 74IAE

Interpretation Introduction

Interpretation:

The possible isotope of element E which has a mass number that is 2.50 times its atomic number and where the atomic number is equal to the mass number of another isotope Y which in turn has an atomic number equal to the neutron number of Se-82 needs to be identified.

Concept introduction:

1. Atoms are composed of fundamental subatomic particles: electrons, protons and neutrons and in general can be described by two quantities: Atomic number (Z) and Mass number (A).

2. For neutral atoms:

Number of protons = Number of electrons = atomic number Z ----- (1).

Number of neutrons = Mass number (A) − Atomic number (A) ----- (2).

3. Ions are charged species that are formed by the loss (positive ion, cation) or gain (negative ion, anion) of electrons.