Its B cold air penetrating the hot water hope it helps
<span>A.H2O = water, so it is a liquid at room temperatures (melting point = 0C) and melting point must be below 20C
B.HCl = A gas at room temperatures, so melting point (-114C) is definitely lower than 20C.
Melting points of the aqueous solution (solution in water) at different concentrations are all below that of water, i.e. 0C.
C.CH4 = A gas at room temperatures, so melting point (-182C) must be below 20C.
D.MgCl2 = A white powdery solid at room temperatures, so its melting point (714C) must be above 20C (So this is the only one among the four choices that melts above 20 ° C).</span>
I believe that this is the answer 520.03 g
B metal is denser, wood will float and so will paper and plastic
You definitely know that is has 56 protons and 56 electrons because atomic number is proton number and protons=electrons
