A garage door opening device has a light near the floor. This light is pointed at a receiver. If a cat runs under the door while it is opening, the garage door stops moving. What property of light applies to this situation? A) The light changes color as it bounces off the cat. B) Light is a wave of energy which is absorbed by objects like the cat. C) Light will change speed when it strikes the cat before it gets to the receiver. D) Light travels in a straight line. The cat blocks the light from getting to the receiver.

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

Select the correct text in the passage. which sentences describe examples of sustainable living? i live in an old apartment building downtown, but my company is based in an office park on the outskirts of the city. i drive an old car that needs to be replaced. i plan to buy a hybrid for better gas mileage, but for now i am able to carpool with a couple of friends from work. the drive to the office park is about 45 minutes each way, but we do get to work in a modern building. the architects just received a leed certification for the design.

Which of the following are correct values for the ideal gas laws constant r