What the concept of electronic transition​

In the 1800s, one of the statements in john dalton's atomic theory was that atoms are indivisible. later experimental evidence led to the discovery of subatomic particles such as neutrons, electrons, and protons. what happened to the indivisible atom part of dalton's atomic theory, and why?

Agas can holds 2.0 gal of gasoline. what is this quantity in cubic centimeters?

Classify this reaction: 2al+n2-> aln.