Which of the following best describes earth tectonic plates ? A. they move away from each other

B They move because of convection currents in the mantle

C. They collide at the mid ocean ridge

D. They form subduction zones

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.

Draw two cyclic constitutional isomers of cis-1

What does the symbol (–hfus) indicate in a phase change?