Answer: Na, S, Cl
Explanation:
Atomic size decreases as one moves from left to right on the periodic table with elements in the same period. This is as a result of the electrons increasing in the outer circle and thus being drawn to the protons in the nucleus which will lead to the outer shell area decreasing.
Sodium (Na) comes before Sulfur (S) which comes before Chlorine (S) so this is the decreasing order as they are all in the same period.
Picoliter is a unit of measurement for liquids.
One picoliter = 1×10⁻⁹ mililiters
So:
19 mL ---- x pL
1×10⁻⁹ mL ---- 1 pL
1×10⁻⁹x = 19
x = 1,9 × 10¹⁰ pL
or 19,000,000,000 pL
Answer: 1.9 × 10¹⁰ pL
C = 4 mol/l
v = 0.5 l
n(NaCl)=cv
n(NaCl) = 4 mol/l · 0.5 l = 2 mol
2 moles of NaCl must be dissolved
