Which chemical formula shows a covalent compound? A. HBr B. CO2 C. MgO D. NaCl

answer

the ions in solute supperate from eachouthere

c (diamond),

sio2 (quartz)

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