A) Which way is the hiker walking in part 1? _ B) How fast is the hiker walking in part 2? _
C) Is the hiker speeding up or slowing down in part 3? _

radiation warms things up temp rises convection currents air circ windy weather

beta is electron from nucleus

something from nucleus has changed, but charge must be same for cons of charge

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.