How many significant figures are in 820 400.0 L

Scientific evidence tells us that the cause of earths four season is the tilt of earth as it revolves around the sun. the student is instructed to illustrate this information in a science notebook. how will the student illiterate winter in the northern hemisphere?

In which block of the periodic table is uranium (u) found? s blockd blockp blockf block

Why is the bottom layer of a trophic pyrimid the