When a scientist is beginning the process what is the key term she or he must ask in order to begin? A: when or where
B:why or how
C: who or how many?
D: which or what

plz help thank you

Working with si (metric) units for each of the following commonly used measurements, indicate its symbol. liter gram milliliter kilogram meter centigram milligram centimeter kilometer second millimeter milliseconds

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Many radioactive atoms that have large masses undergo radioactive decay by releasing a particle that is identical to a helium-4 nucleus. what changes in the original atom are expected as a result of this natural phenomenon? the atomic number and the mass number will decrease. the atomic number and the mass number will increase. the atomic number will increase, and the mass number will decrease. the atomic number will decrease, and the mass number will increase.