Answer:
1. As white light passes through our atmosphere, tiny air molecules cause it to 'scatter'. Therefore, blue light is scattered more than red light and the sky appears blue during the day.
2. We can see the moon during the day for the same reason we see the moon at night. The surface of the moon is reflecting the sun's light into our eyes. When we see the moon during the day it's because the moon is in the right spot in the sky and it's reflecting enough light to be as bright, or brighter, than the sky.
3. At eight pounds per gallon, that's another 38,593,169,564 pounds of water in the air. Add it all up, and the total weight of our sky is 12,107,415,382,493,169,564 pounds, more than 12 quintillion pounds!
4. 5.972 × 10^24 kg
5. Four forces keep an airplane in the sky. They are lift, weight, thrust and drag. Lift pushes the airplane up.
6. Water is wet, in the sense of being a liquid which flows easily, because its viscosity is low, which is because its molecules are rather loosely joined together.
7. Rainbows are formed when sunlight is scattered from raindrops into the eyes of an observer. The lower the sun in the sky the more of an arc of a rainbow the viewer will see. Rain, fog or some other source of water droplets must be in front of the viewer.
8. Birds can sit on power lines and not get electric shocks because the electricity is always looking for a way to get to the ground. The birds are not touching the ground or anything in contact with the ground, so the electricity will stay in the power line.
Explanation:
. This yields an average atomic mass of 79.903 amu. This procedure is general; whenever we have many types F of a specific genre G, the mean of the genre G can be calculated by: 
is the proportion of type i in the genre G. In this example, Br79 and Br81 are the 2 types and the genre is Bromine.