What is created when cemical reactions join atoms together

Chemical Compound

Explanation:

Chemical compound is formed when two or more atoms either from the same element or from different element join together  through ionic, covalent bond, hydrogen or any other physical or chemical bond  

for Instance -  

Atoms of hydrogen combines with oxygen to form water  through covalent bonding (sharing of electrons) between H and O.

Atoms of sodium  combines with chlorine to produce sodium chloride through ionic bond (complete transfer of electron) between Na and Cl.

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.