Please solve a) and b) correctly

Question

An unknown radioactive element decays into non-radioactive substances. In  days the radioactivity of a sample decreases by  percent.

(a) What is the half-life of the element?

half-life:____________ (days)

(b) How long will it take for a sample of  mg to decay to  mg?

time needed:___________ (days)

Answer 1

a) 1000 days

b) 14.5 days

things that have half life are things where the more stuff there is the quicker it disappears. Imaging a sink with soapy water that is draining at the same time a water is being added. Because the new water and soapy water mix before the water drains it gets less soapy at a different rate depending on how much soap there is in the water.

beginning GETS LESS SOAPY FAST but toward the end (tinny tinny bit of soap left) it will get less soapy only a little bit at a time.

If something has a half life, it means that it takes x amount of time to have half the amount. In our example the soap has a half life. if the half life was 10 min, that would mean that in10 min, 2Tbsp of soap in the water would be 1Tbsp of soap. It also means that in 10 min 1Tbsp would become 0.5Tbsp of soap. 10 min is the half life so in 10 min there will be half of what was before.