About how many years did it take to update the model of an atom from the "simple model" to the "plum pudding model"?

89 years

Explanation:

In 1808, John Dalton said that atoms were a solid sphere. It was until 1897 that J.J. Thompson discovered there were electrons, he said these electrons were scattered around in the atom like a plum pudding.

answer: dinosaur

explanation

their extinction was caused by massive asteroid that fell on earth

chordata is the answer