If a radioactive isotope has a half-life of 20 million year, and there is 25% remaining in the igneous rock. How old is the rock?

Lucia is walking barefoot in her yard. she accidentally steps on a nail. how will her nervous system work to generate a reaction? arrange the eventschronologically.

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?

Which label identifies the part of the atp molecule that changes when energy is released in the cells of all living things