Answer:
pour the rock salt mixture throught a filter made from paper and allow the liquid to filtrate .
Explanation:
Separating Sand and Salt
Probably the easiest method to separate the two substances is to dissolve salt in water, pour the liquid away from the sand, and then evaporate the water to recover the salt.
Groups 13 through 18 are the constitute p-block
Isotopes are forms of the same elements which contain equal number of protons but different number of nucleus in their nuclei, thus the differ in relative atomic mass but they have same chemical properties. The mass number is the summation of number of proton and number of neutron of an atom. If the mass number is known, then one need to know the number of proton in the atom in order to calculate for the number of neutron.
Argon has 18 protons which identifies the element and is in group Noble Gases which has 8 valence electrons.