Question

Give the number of protons and the number of neutrons in the nucleus of each ofthe following isotopes: (a) Aluminum-25 (b) Technetium-95 (c) Tin-120 (d) Mercury-200

Answer 1

The number of protons in an isotope is equal to its atomic number, while the number of neutrons is found by subtracting the atomic number from the isotope's mass number. Applying this, for Aluminum-25 there are 13 protons and 12 neutrons, for Technetium-95 there are 43 protons and 52 neutrons, for Tin-120 there are 50 protons and 70 neutrons, and for Mercury-200 there are 80 protons and 120 neutrons.

Step-by-step explanation:

The student is asking to determine the number of protons and the number of neutrons in the nucleus of each given isotope. An isotope's name usually consists of the element's name followed by the mass number (sum of protons and neutrons). The atomic number denotes the number of protons and for a neutral atom, it also denotes the number of electrons. Given this, we can identify the number of neutrons in an isotope by subtracting the atomic number (the number of protons) from the mass number.

(a) Aluminum-25: Aluminum (Al) has an atomic number of 13, indicating it has 13 protons. Aluminum-25 has a mass number of 25. The number of neutrons can be found by subtracting the atomic number from the mass number: 25 - 13 = 12 neutrons.

(b) Technetium-95: Technetium (Tc) has an atomic number of 43, so it has 43 protons. Technetium-95 has a mass number of 95. To find the number of neutrons: 95 - 43 = 52 neutrons.

(c) Tin-120: Tin (Sn) has an atomic number of 50, thus 50 protons are present. For Tin-120, the neutron count is 120 - 50 = 70 neutrons.

(d) Mercury-200: Mercury (Hg) has an atomic number of 80. With Mercury-200, the number of neutrons is 200 - 80 = 120 neutrons.

Answer 2

Answer:(a)Aluminium-Al has 12 protons and 13neutrons (b) Technetium-Tc has 43 protons and 52neutrons (c) Tin-Sn has 50protons and 70 neutrons (d) Mercury - Hg has 80protons and 120neutrons

Explanation:

All elements on the periodic table are are arranged in terms of atomic number.

For a neutral atom( uncharged atom) , atomic number is the same as proton number. And the sum of number of proton and number of neutrons gives mass number.

Isotopes exist as a result of difference in mass number of atoms but the same atomic number, which implies isotopes of an element always have the same number of protons but different neutron numbers.

(a) Aluminum-25 has a mass number of 25 with atomic number of 12.

Since its a neutral atom, number of protons is 12 while neutron number can be deduced as,

Mass number = neutron number+ proton number

Neutron numbers= mass number - proton number

Neutron number= 25-12=13neutrons

(b) Technetium -95 has a mass number of 95 with atomic number of 43.

Since its a neutral atom, number of protons is 12 while neutron number can be deduced as,

Mass number = neutron number+ proton number

Neutron numbers= mass number - proton number

Neutron number= 95-43=52neutrons

(c) Tin-120 has a mass number of 120 with atomic number of 50

Since its a neutral atom, number of protons is 50 while neutron number can be deduced as,

Mass number = neutron number+ proton number

Neutron numbers= mass number - proton number

Neutron number= 120-50=70neutrons

(d) Mecury-200 has a mass number of 200 with atomic number of 80.

Since its a neutral atom, number of protons is 80 while neutron number can be deduced as,

Mass number = neutron number+ proton number

Neutron numbers= mass number - proton number

Neutron number= 200-80=120neutrons