How many grams of magnesium acetate (Mg(CH3CO2)2) do you need to dissolve in a total volume of 250 mL water to make a solution with a concentration of 0.300 M ? Note: the relative molar mass (Mr) of Mg(CH3CO2)2 is 142.394 g/mol.
1.90 g
16 084 g
119 g
16.1 g
10.7 g
171 g

Liquid helium

Explanation:

Liquid helium is known to be the coldest element in the world.

It has a ridiculous boiling point of -452 degrees

It is considered the only element on earth that does not freeze to become solid. normally, it is usually in a form of cryogenic fluid or superfluid.

Hence, the coldest element is known as LIQUID HELIUM

it is b that is the answer.