Answer:
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
Explanation:
Answer:
I think the answer would be A.
Answer: isotopes
Explanation: I remember this from when I took honors chemistry, they are know as isotopes.
Electron has the smallest mass
Answer:10,0000 years
Explanation:
If it takes 2000 years to weather 1cm of limestone
It will take 5*2000 years to weather 5cm of limestone. This gives us 10000 years.
