How do we determine the amount of dark matter in elliptical galaxies?

Which notation is used to represent an alpha particle? a. b. c. d.

Lightning is an example of what phenomenon? a release of a large amount of energyan absorption of a large amount of energya natural electric circuita natural electric current

Chameleons catch insects with their tongues, which they can rapidly extend to great lengths. in a typical strike, the chameleon's tongue accelerates at a remarkable 220 m/s2 for 20 ms, then travels at constant speed for another 30 ms.