What property of carbon cycle makes it a good illustration of conservation of matter

Hydrogenation reactions, in which h2 and an "unsaturated" organic compound combine, are used in the food, fuel, and polymer industries. in the simplest case, ethene (c2h4) and h2 form ethane (c2h6). if 140 kj is given off per mole of c2h4 reacting, how much heat (in mj) is released when 12 kg of c2h6 forms?

1) a light bulb takes in 30 of energy per second. it transfers 3j as use energy. calculate the efficiency. second. it transfers 3j as useful light energy and 27j as heat energy. calculate the efficiency

Four statements about the development of the atomic model are shown below. a: electrons have wavelike properties. b: atoms have small, negatively charged particles. c. the center of an atom is a small, dense nucleus. d: atoms are hard, indivisible spheres. which order of statements represents the historical development of the atomic model? c-d-a-b c-d-b-a d— в-а — с d-b-c-a