The last one should be the correct answer
Answer:

Explanation:
To solve this equation we can use Graham's Law of effusion to calculate the molar mass of the chloroflourocarbon

Which chloroflorocarbon has this molar mass?
C2Cl2F4
Fe(No3)2 because Fe(No3)2 is soluble
Answer:
Mercury is an liquid metal
Explanation:
Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum.
Symbol: Hg
Answer:
5.0×1022 sa taas po yang 22