Question

An element has 17 protons and its two isotopes have 18 and 20 neutrons. what is the ratio of average atomic mass to atomic number of this element if both isotopes exist equally?​

Answer 1

sorry I am busy so I will give you answer later

Answer 2

Answer:

The ratio of average atomic mass to atomic number of this element is equal to 2.12.

Explanation:

Given, the number of protons in an element = 17

Number of protons = atomic number

Therefore, the atomic number of the given element = 17

Isotopes of an element has same atomic number but different atomic mass.

Now the number of neutrons in 1st isotope = 18

Therefore, the atomic mass of 1st isotope  = 17 + 18 = 35

Number of neutrons in 2nd isotope = 20

Therefore, the atomic mass of 2nd isotope  = 17 + 20 = 37

Average atomic mass = [atomic mass × abundance(%)]/100

Given, both isotopes exist equally, So the abundance of both isotopes is equal.

Average atomic mass $=\frac{(35)(50)+(37)(50)}{100}=36$

Therefore, the ratio of average atomic mass to atomic number of this element :-

∴   $\frac{Average \; atomic\; mass}{Atomic \; number}=\frac{36}{17}=2.12$