Answer:
Matter or energy can change from one form to the other
Explanation:
The law of conservation of energy states that energy can neither be created nor destroyed but can only be transformed i.e. changed from one form to another. For example, mechanical energy can be changed to electrical energy.
Likewise, the law of conservation of mass/matter states that matter can not be destroyed or created but can change via physical or chemical means to conserve it. For example, matter can change from liquid state to gaseous state.
From the above two laws, it can be said that "matter or energy can change from one form to the other".
I think I would agree on horses, just because you can take them for lessons, ride them treat them like a pet. Donkeys you can’t ride but you can have as a pet. Horses you can make money off, like races, but aren’t influenced. You can rent out horses to people that don’t have anywhere to place them.
well none its made from iron nut i would go with c. a solution sorry if im wrong tell me in comments
Answer: It will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams
Explanation:
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Half life is represented by 

= rate constant
Given : Strontium-90 decreases in mass by one-half every 29 years , that is half life of Strontium-90 is 29 years.
As half life is independent of initial concentration, it will take 29 years for a 10.0-gram sample of strontium-90 to decay to 5.00 grams as the amount gets half.