Which of the following elements are considered to be the most highly reactive? a. an element with two electrons missing from its outer shell b. an element with a complete outer shell c. an element with one electron missing from its outer shell d. an element with three electrons in its outer shell

Facilitates growth and change in neurons and the migration of neurons to different sites in the brain

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.

The most famous fossil called archaeopteryx is which of the following? a dinosaur a fern a fish a bird