Atrain travels 98 kilometers in 1 hours, and then 78 kilometers in 3 hours. what is its average speed? this is a fill in the blank question.

In a classical model of the hydrogen atom, the electron moves around the proton in a circular orbit of radius 0.053 nm. what is the electron's orbital frequency? what is the effective current of the electron?

Which component of the earth’s atmosphere is decreased due to photosynthesis?

Daughter element the new element produced along with a decay particle in a nuclear transmutation 2. half-life the substance that decays in a nuclear transmutation 3. parent element the change of one chemical element into another by nuclear decay or radioactive bombardment 4. transmutation the time required for the decay of one-half of the atoms in a sample of radioactive material