How many half-lives have passed if a rock contains 25% parent isotopes and 75% daughter isotopes?

If vegetable oil is made out of veggies, then what is baby oil made out of?

Biomass can be used to generate electricity. biomass relies heavily on agricultural crops. plants release carbon dioxide and water in combustion. plants use photosynthesis to originally generate the energy that is needed. the chemical energy of these plants all started with what energy source?

The hematodinium parasite becomes less of a problem for the blue crab when the crab is very young. fishing is thriving in the region. the crab moves to less salty water. a significant percentage of the population is impacted.