Hey There!
Expand soluble ions to get complete ionic equation:
Sn²⁺(aq) + 2 NO³⁻(aq) + 2 K⁺(aq) + S²⁻(aq) :
SnS(s) + 2 K⁺(aq) + 2 NO³⁻(aq)
Cancel common ions to get net ionic equation:
Sn²⁺(aq) + S²⁻(aq) => SnS(s)
Hope that helps!
Explanation:
Moving from left to right across a period, the atomic radius decreases. The nucleus of the atom gains protons moving from left to right, increasing the positive charge of the nucleus and increasing the attractive force of the nucleus upon the electrons.
TLDR: the answer is C. 22,920 years.
Half-life describes the amount of time for a radioactive substance to decay to one-half of the original substance’s weight. So, if we had 100g of C-14, after 5,730 years, only 50g remain; after another 5,730 years, only 25g would remain, and so on.
In this problem, we are meant to assume that the original amount of C-14 was 64g, and that, through decay, it forms N-14. We can figure out how many half lives have passed by figuring out how much 4 is out of 64 by dividing 64 by two repeatedly. Each time, count a half life.
64 - 32 (1 HL) - 16 (2 HL) - 8 (3 HL) - 4 (4 HL)
In this problem, 4 half lives have passed. We can now multiply this by the time for one half life to find how many years have passed.
4 x 5,730 = 22,920 years
Approximately 22,920 years have passed since the drawing was created.