Identify whether the statement is true or false, and why? “Global sea levels have not changed in the past, the fact that they are rising now could be very dangerous.”
A. False, it should read “Global sea levels have changed in the past, the reason they are dangerous now is because the change is occurring very fast.”
B. True
C. False, it should read “Global sea levels have changed in the past, but they are not changing today.”
D. False, it should read “Global sea levels have risen very quickly in the past, so the change today could be very dangerous, but is not caused by humans.”

Hydrogen is the most abundant element on the periodic table..hope it .

Answers are 1,2,4 its correct on edgenuity.

Answerthis solution will not form a precipitateexplanationsolubility equilbrium:         pbf₂(s)  ⇄ pb²⁺(aq) + 2 f⁻(aq)the solubility product expression is    (we exclude solids from the equilibrium expression).now suppose we have the trial ion product q, which we can define as    then, we can interpret  q as the product of the concentration of the ions that we have and ksp as the product of the ion concentrations that are needed to form a saturated solution.if q > ksp, then that implies that there will be a surplus of ions that exceed the amount that is required to form a saturated solution. a precipitate will then form (the precipitate continually  forms until the surplus ions are removed and q is decreased to ksp's value).if q = ksp, the saturated solution that forms is barely saturated and the precipitate will be minimal.if q < ksp, then the ion concentration will not be enough to form a saturated solution (so no precipitate).using our information, we calculate the trial ion product:     since q = 2.7  × 10⁻⁸ < ksp =  4  ×  10⁻⁸, a precipitate will not form.