When a sperm cell joins an egg cell, occurs

The sperm fertilizes the egg forming a new cell. The new cell that forms is called a zygote.

Explanation:

it should be p1 v1 = p2 v2

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer