Radium has a half-life of 1,620 years. in how many years will a 1 kg sample of radium decay and reduce to 0.125 kg of radium?

3,240 years

6,480 years

4,860 years

1,620 years

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

What are some possible short and long term medical concerns for crew members on longer space exploration trips

Which particle controls what element an atom is?