The line spectrum is created when an electron moves from level to level.

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

What term is applied to a scientist who studies ancient life, including animal and plant fossils a. anthropologist b. dendroclimatologist c. geophysicist d. paleontologist

The chemical equation below shows the reaction of sodium (na) and chlorine (cl) to form sodium chloride (nacl). 2na + cl2 → 2nacl in this equation, which of the following is a reactant? i. sodium ii. chlorine iii. sodium chloride