The rounded atomic mass of K is
K stands for and has valence electron(s).

Potassium

k = Potassium

Potassium Has 19 Electrons

the atomic mass is 39.0983

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue