Question

From the bellow reaction equation, what is the value of $Z$?
${}_{27}^{60}Co{\to }_Z^{60}X+e^{-}$

• A. 25
• B. 26
• C. 27
• D. 28
• E. 29

Answer 1

The correct option is D 28

From the bellow reaction equation, the value of $Z$ is 28.
${}_{27}^{60}Co{\to }_Z^{60}X{+}_{-1}^{0}e$
$Z$ represents the atomic number of the element $X$.
The sum of the atomic numbers on left hand side of the equation is equal to the sum of the atomic numbers on right hand side of the equation.
$27=Z+(-1)$
$Z=27+1=28$