What is the significance of carbon having four valence electrons? A. The outermost shell is full, making it a stable.
B. The outermost shell never fills making it unstable.
C. The outermost shell can only bond with hydrogen.
D. The outermost shell can form up to four covalent bonds.

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.

Any sound above what db can cause hearing loss in human beings

All ova contain sex chromosomes corresponding to: x y xx xy