The amount of energy required to heat water for a 10-minute shower (50 gallons) is 2.2125 kj. how many calories is this?

From the problem statement, this is a conversion problem. We are asked to convert from units of kilojoules to units of calories. To do this, we need a conversion factor which would relate the different units involved. We either multiply or divide this certain value to the original measurement depending on what is asked. From literature, we will find that 1 kilojoule is equal to 239 calories. We do as follows:

2.2125 kJ ( 239 calories / 1 kJ ) = 528.79 calories

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

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

C) electrons encircling a nucleus with neutrons and protons