Question

Which of the following elements has the highest atomic mass?

A) fluorine
B) beryllium
C) aluminum
D) argon

Answer 1

argon has the highest atomic mass (39.9)

F (19.0)
Be (9)
Al (27.0
Ar (39.9)

Answer 2

Atomic mass increases as the atomic number increases, this is because that atomic number repersent the amount of protons in the atomic,

out of these 4 choices
F(9)

Be(4)

Al(13)
Ar(18)

The atomic mass is usually more than double of the atomic number, Therefore you can confirmed that argon has the highest atomic mass out of the 4 given options