Question

The mass number 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:
A. `.(24)Cr, ._(33)As`
B. `._(24)Cr, ._(34)Zn`
C. `._(19)K,._(33)As`
D. `._(29)Cu,._(30)Zn`

Answer 1

Correct Answer - A
Element(X) `._(x)^(52)X`
Number of protons=x
Number of neutrons `=(52-x)`
Number of neutrons `=(116.6)/(100)xx x`
`therefore(52-x)=(116.6)/(100)xx x`
`x=(52)/(2.166)=24`
`therefore` Element x is `_(24)Cr`.
Element (Z)` ._(x)^(75)Z`
Number of protons=x
Number of neutrons =(75-x)
Number of neutrons`=(127.3)/(100)xx x`
`(75-x)=1.273x`
`x=(75)/(2.273)=33`
`therefore` Element `Z=._(33)As`