Which scientist developed a model of the atom that looked like a nucleus surrounded by electrons?

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

How can carbon move from "land" to bodies of water? describe the way human impact has lead to increased levels of co2 in the atmosphere.