Is the Vitamin D that our skin makes when exposed
to the sun's rays natural or synthetic?

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

Select the correct answer. when carbon dioxide dissolves in water, it sometimes reacts with water to form carbonic acid as in this balanced equation: co2 + h2o → h2co3. if 495 milliliters of carbon dioxide at 25°c and 101.3 kilopascals reacts with excess water, what is the theoretical yield of carbonic acid? use the periodic table and the ideal gas resource a. 0.889 g b. 1.10g c. 1.27g d. 2.02g what's the answer! quick!

What is the binding energy of a nucleus that has a mass defect of 5.81*10-^29 kg a 5.23*10-^12 j b 3.15* 10^12 j c 1.57*10-3 j d 9.44*10^20 j