Answer:
The answer is below
Explanation:
The half life of a substance is the time required by that substance to reduce to half of its initial value. The half life is calculated using the formula:

Given that t = 87 years, half life = 29 years, therefore the quantity of strontium-90 left is:

That is one-eight of Strontium 90 would be left after 87 years
Trash cans, dumps, anything to do with getting rid of unneeded waste
Serotonin and n<span>orepinephrine.
Serotonin decreases appetite by activating </span>5-HT2C receptors<span> on dopamine-producing cells which will cause dopamine release to stop. Dopamine is responsible for the increase of appetite, therefore, serotonin decreases appetite.
Norepinephrine by increasing the production of glucose it also causes the body to feel satiety and, therefore, decreases the appetite.</span>