HELP PLEASE The graph below shows the radioactive decay of
rubidium-87.
Number of Half-lives
What percentage of rubidium-87 atoms will be left
after four half lives?
(1) 25.0%,
13) 6.25%
(2) 12.5
(4) 3.125%

Melissa lives in a town called greendale. she discovers that when she lights a match and holds it near her kitchen faucet, the little flame grows into a larger fire. melissa is surprised because she thought the water would extinguish the flame rather than ignite it further. her mother tells her that the water might be contaminated with dissolved methane, a primary component in natural gas. melissa investigates the matter and finds that cases of methane contamination started shortly after a company began fracking for natural gas in the area. based on this information, which three statements are plausible consequences of fracking in greendale?

The normal shape of an enzyme is as shown in structure a. if the enzyme’s shape changes to that shown in structure b, what are two consequences of this change?

In which order does sexual reproduction take place in plants? a. pollination, germination, fertilization b. germination, fertilization, pollination c. pollination, fertilization, germination d. fertilization , pollination, germination