Which of the following is the correct word equation for the reaction described below? Calcium hydroxide and hydrogen gas are produced by the reaction of calcium hydride and water.

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

Arollercoaster car at the top of a hill has potential energy kinetic energy chemical energy light energy