What occurs in a chemical reaction?

From center station, a train departs every 30 minutes on the fast line and a train departs every 50 minutes on the state line. if two trains depart from center station at 8: 00 a.m., one on each of the two lines, what is the next time that two trains, one on each line, will depart at the same time?

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

The plum pudding model of the atom states that ?