Chapter U1.14, Problem 3E

Interpretation Introduction

Interpretation:

Stable isotopes of given elements have to be found based on the isotope graph.

Concept introduction:

An atom or an element exists in many isotopic forms. Some isotopes are found naturally on Earth while some exist due to human activity. Isotopes differ in the number of neutrons in the nucleus of the atom. Some isotopes have stable nuclei while some have unstable nuclei.

Answer to Problem 3E

Oxygen, O has 3 stable isotopes.

Neodymium, Nd has 5 stable isotopes

Copper, Cu has 2 stable isotopes

Tin, Sn has 10 stable isotopes

Explanation of Solution

Given information:

Following elements are given:

Oxygen neodymium, copper and tin

Elements are found in one or more isotopic forms. Some isotopes have stable nuclei while some have unstable nuclei.

Stability of nucleus determines the stability of an isotope. Unstable nucleus will disintegrate. There should be a balance between the number of protons and number of neutrons to have a stable nucleus. Large atoms need more neutrons to make stable nuclei.

From the isotope graph following observations are made:

1. Oxygen - It has 8 protons. There are 3 stable isotopes seen on the graph; with 8, 9 and 10 neutrons.
2. Neodymium, Nd has 5 stable isotopes. It has 60 protons. The graph shows 5 stable isotopes with 82, 83, 85, 86 and 88 neutrons.
3. Copper has 29 protons. The graph shows 2 stable isotopes of copper with 34 and 36 neutrons.
4. Tin with 50 protons has maximum number of stable isotopes. The graph shows 10 stable isotopes.

Conclusion

Each element has different number of isotopes. Some isotopes are stable while some are radioactive; some isotopes are abundantly available on earth while some are rare.