82.6 I'm sure since your rounding to the nearest whole number
Intertidal zone on a rocky shore, with plants and animals typically found there. The intertidal zone is the area of the marine shoreline that is exposed to air at low tide, and covered with seawater when the tide is high.
Draw a diagram showing marbles (being stars) farther away but around books (being planets).
5 grams will be left. After the first 1000 years, there will be half of 20 left, or 10. After 2000 years, half of 10 will remain, which is 5.