Asolution has a volume of 250 ml and contains 0.70 mol nacl what is the molarity

First convert mL into liters:

1 L = 1000 mL

250 mL / 1000 = 0.25 L

M = n / V

M = 0.70 / 0.25

M = 2.8 mol/L⁻¹

hope this helps!

The molecules contain like 54 of water 

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.