Which statement describes an ionic bond?

a.

electrons transition from an inner shell to a valence shell.

b.

electrons are transferred from one atom to another.

c.

electrons are shared between atoms.

d.

electrons are mobile within a metal.

Based on the topographic map of mt. st. helens, what is the contour interval of the volcano about height is 2,950 m?

The blue particles in this image are able to cross the cell membrane through simple diffusion. how will they be transported? outside the cell inside the cell o a. the substances will move directly across the membrane from outside the cell to inside the cell. b. the substances will move through channels in the membrane proteins from outside the cell to inside the cell. o c. the substances will move through channels in the membrane proteins from inside the cell to outside the cell. o d. the substances will move directly across the membrane from inside the cell to outside the cell.

Which short-term environmental changes would a very small asteroid or comet impact on earth most likely cause? check all that apply. flooding extinction craters on surface changes in weather patterns death of organisms and populations