Which of the following is a use of radioactive isotopes?
a.
can determine the ages of rocks and fossils
b.
can be used to treat cancer and kill bacteria that cause food to spoil
c.
used as “tracers” to follow the movements of substances within organisms
d.
all of the above

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

1. what is the relationship between the shape of an enzyme and the reactions they catalyze?

2. how does an enzyme inhibitor work?

separate your answers so i dont get confused : )