Question

5. Common (most stable) mass numbers of the following elements are Al-27, Pt-195, Co-59,

Answer 1

Answer:

Number of neutrons of Al²⁷₁₃ = 14

Number of neutrons of Pt¹⁹⁵₇₈= 117

Number of neutrons of Co⁵⁹₂₇= 32

Number of neutrons of Ag¹⁰⁸₄₇= 61

Number of neutrons of Au¹⁹⁷₇₉ = 118

Explanation:

We know that atomic number of an atom is number of electron or protons while atomic mass is sum o number of neutrons and and protons.

Shorthand notations of given elements:

Al²⁷₁₃

This notation shows that atomic number of Al-27 is 13 and atomic mass is 27.

Number of neutrons of Al²⁷₁₃  = 27 - 13

Number of neutrons of Al²⁷₁₃ = 14

Pt¹⁹⁵₇₈

This notation shows that atomic number of Pt-195 is 78 and atomic mass is 195.

Number of neutrons of Pt¹⁹⁵₇₈  = 195 - 78

Number of neutrons of Pt¹⁹⁵₇₈= 117

Co⁵⁹₂₇

This notation shows that atomic number of Co-59 is 27 and atomic mass is 59.

Number of neutrons of Co⁵⁹₂₇  = 59 - 27

Number of neutrons of Co⁵⁹₂₇= 32

Ag¹⁰⁸₄₇

This notation shows that atomic number of Ag-108 is 47 and atomic mass is 108.

Number of neutrons of Ag¹⁰⁸₄₇  = 108 - 47

Number of neutrons of Ag¹⁰⁸₄₇= 61

Au¹⁹⁷₇₉

This notation shows that atomic number of Au-197 is 79 and atomic mass is 197.

Number of neutrons of Au¹⁹⁷₇₉  = 197 - 79

Number of neutrons of Au¹⁹⁷₇₉ = 118