Question

Please help on this one?

Answer 1

Answer:

C

Explanation:

Answer 2

Answer:

$\text{C. } _{36}^{85}\text{Kr}$

Explanation:

Your nuclear equation is  

$_{35}^{85}\text{Br} \longrightarrow \, _{-1}^{0}\text{e} +\, _{x}^{y}\text{X}$

The main point to remember in balancing nuclear equations is that

• the sum of the superscripts and must be the same on each side of the equation.
• the sum of the subscripts must be the same on each side of the equation.  

Then  

85 = 0 + y, so y = 85 - 0 = 0  

35 = -1 + x, so x = 35 + 1 = 36

The nucleus with atomic number 36 and atomic mass 85 is krypton-85.  

The nuclear equation becomes  

$_{35}^{85}\text{Br} \longrightarrow \, _{-1}^{0}\text{e} + \, _{36}^{85}\text{Kr}$