Asample of phosphorus-32 has a half-life of 14.28 days. if 55 g of this radioisotope remain (1 point) unchanged after approximately 57 days, what was the mass of the original sample? 

Asample of a gaseous substance changes into liquid. this process is called (blank) and it takes place when heat is (blank) a gaseous system

Mutt and jeff are running along a path each pushing a cart loaded with rocks. if mutt's wagon has a mass two times greater than jeff's and they want to stay together, arriving at their destination at the same time, what must happen? a) jeff should slow down so mutt can catch up. b) mutt must use half as much force to push his cart. c) mutt must use twice as much force to push his cart. d) mutt and jeff will use the same force, but mutt will take bigger steps.

The heliocentric and the geocentric models of the solar system included these central principles