Question

Write isotopic symbols of the form AZX for each isotope.

A-the magnesium isotope with 14 neutrons Express your answer as an isotope.

B-the nitrogen isotope with 8 neutrons Express your answer as an isotope.

C-the silicon isotope with 15 neutrons Express your answer as an isotope.

D-the xenon isotope with 77 neutrons Express your answer as an isotope.

Answer 1

Isotopes are the compounds with the same number of protons but the different number of neutrons.

Eg. ¹²₆C and ¹³₆Care the isotopes with 6 and 7 neutrons respectively and 6 protons in each.

A) Given, Magnesium isotope with 14 neutrons.

From the periodic table,

The atomic number of magnesium(Z) = 12

The atomic number is nothing but the number of protons.

Now, the mass number(A) of isotope = Number of protons + Number of neutrons

mass number(A) of isotope = 12+ 14

mass number(A) of isotope = 26

Thus, the isotopic symbol is ²⁶₁₂Mg

B) Given, Nitrogen isotope with 8 neutrons.

From the periodic table,

The atomic number of Nitrogen = 7

The atomic number is nothing but the number of protons.

Now, the mass number(A) of isotope = Number of protons + Number of neutrons

mass number(A) of isotope = 7 + 8

mass number(A) of isotope = 15

Thus, the isotopic symbol is ¹⁵₇N

C) Given, Silicon isotope with 15 neutrons.

From the periodic table,

The atomic number of Silicon = 14

The atomic number is nothing but the number of protons.

Now, the mass number(A) of isotope = Number of protons + Number of neutrons

mass number(A) of isotope = 14 + 15

mass number(A) of isotope = 29

Thus, the isotopic symbol is ²⁹₁₄Si

D) Given, xenon isotope with 77 neutrons,

From the periodic table,

The atomic number of xenon = 54

The atomic number is nothing but the number of protons.

Now, the mass number(A) of isotope = Number of protons + Number of neutrons

mass number(A) of isotope = 54 + 77

mass number(A) of isotope = 131

Thus, the isotopic symbol is ¹³¹₅₄Xe