Round the value 44.981 g to three significant figures.

45.0

Explanation:

Using the rules of rounding, we can round 44.981 to 45. We need that third sig fig though, so we add the trailing zero

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