2. The heat energy fequired to change a unit mass of a solid into a liquid at
constant temperature is called
(1) heat of vaporization
(2) heat of formation
(3) heat of solution
(4) heat of fusion

where's the diagram?

pla·gia·rism

/ˈplājəˌrizəm/

learn to pronounce

noun

the practice of taking someone else's work or ideas and passing them off as one's own.

explanation:

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

since electrons are negative the answer is neagtaive