Mass number is the sum of protons and neutrons.
Atomic number is the total number of protons present.
Mass number = protons + neutrons
Atomic number = protons present.
From the above equations we can conclude that,
Atomic number= Mass number- neutrons.
Thus we can find out the atomic number by subtracting the number of neutrons from the mass number.
PbCl₂(aq) → Pb²⁺(aq) + 2Cl⁻(aq)
NaCl(aq) → Na⁺(aq) + Cl⁻(aq)
Pb²⁺(aq) + 2Cl⁻(aq) ⇄ PbCl₂(s)
At increase the concentration of chloride ions - concentration of lead ions decreases, the lead chloride is formed.
Answer:
B. Na and Li
Both are group I elements.
Its going to be 2.81 x 1023 atoms
