Which of the following pairs of elements is most likely to form an ionic bond a( phosphorus and bromine
b(calcium and bromine
c( carbon and chlorine
d(silicon and oxygen

it is calcium and bromine

Explanation:

this is because they are both ionic compounds

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023 

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