As scientists have learned more than atoms, models of atoms have changed. One of the first atomic models was a solid ball, such as a marble. What are two limitations of using a marble to model an atom?

Which form of relativism states that people rely on their own standards of right and wrong when making a decision?

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

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