The mass numbers of two elements X and Z are 52 and 75 respectively . X contains 16.6% more neutrons compared to protons . Z contains 27.3% more neutrons compared to protons . X and Z are respectively

Options

A. `""_(24)Cr_(133)` AS
B. `""_(24)Cr_(130)` Zn
C. `""_(19)K_(133)` AS
D. `""_(29)Cu_(130)` Zn

Answer

A

Explanation

Given mass number of X = 52
Mass number of Z = 75
Suppose number of protons in X = a
`:. ` Number of neutrons = 0.166 a+a=1.166 a
As we know that
Mass number = Number of proton + Number of neutron
`:.` 52 = a+1.166 a
52 = 2.166 a
a= 24
Thus the element X = `""_(24)Cr`
[` because ` atomic number = number of protons or electrons ]
Similarity for the element Z
75= b +1.273 b = 2.273 b
b = 32.9 `~~`33
Thus the element Z is `""_(33)` As .