What evidence of a chemical change is observed when rust forms on iron

Calculate the energy for the transition of an electron from the n = 8 level to the n = 4 level of a hydrogen atom.

A mass oscillates on the end of a spring, both on earth and on the moon. where is the period the greatest?

Which of the following is an instance of persuasive speaking? a. a coach reviewing the offensive plays for next week's game b. a lawyer explaining the details of a plea bargaining agreement to her client. c.

Does geosphere burn things?

The spectrum produced by a prism or a raindrop is evidence that the average speed of light in the material depends on the light's A. transmission qualities. B. color. C. wave nature. D. particle nature.

Which type of wave experiences a change in speed when entering a new medium? a) only sound waves b) both sound and light waves c) only light waves d) neither sound or light waves

Three basic classes of collisions include all but which of the following?

How does the use of biomass energy to create electricity harm the environment

Which physical property of iron made it popular for use in weapons? 1. Magnetism 2. Luster 3. Malleability 4. Ductility

a 2 kg rock is dropped from the top of a 30 m High building calculate the ball at the time that it strikes the ground