What important change in the atmosphere occurred during the Proterozoic Eon? A. Helium escaped into space and hydrogen was bound into water molecules
B. Nitrogen and carbon dioxide levels decreased, fueling bacteria growth
C. Carbon dioxide levels increased, causing glaciation that cooled the planet
D. Methane levels decreased and oxygen levels increased, promoting aerobic life forms

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b. refraction c. diffraction d. interference

The arrival of in the early days of europa’s existence could have formed its ocean. it is likely that the water experienced similar to earth. it is also possible that this water is retained beneath europa’s surface and in its atmosphere due to europa’s . 1.) a. precipitation b. water vapor c. icy debris 2.) a. gravitational compression b. biochemical cycling c. radiogenic heating 3.) a, gravity b. magnetic field c. heat energy for plato

A10 kg box initially at rest is pulled 18 meters across a horizontal, frictionless surface by a 40 n force. what is the block’s final velocity over the 18 meters?