What U.S. population group is at highest risk for vitamin D deficiency?

Which part of the eye contains billions of molecules of vitamin A?

Vitamin K is 

How many core electrons does an atom of beryllium (Be) contain?

0.5060 grams of liquid cyclohexanol (C6H11OH) undergo complete combustion in a bomb calorimeter. The calorimeter assembly has a heat capacity of 827.0 J/° C and contains exactly 1000 grams of water. What is the final temperature if the initial water temperature is 24.98 ° C? The heat of combustion of the cyclohexanol is –3727 kJ/mol.

Calculate the heat evolved in the reaction (q). (absolute value, no units) 

Which of the following equations would NOT be used to determine the ΔHrxn of CH₄ (g) + NH₃ (g) → HCN (g) + 3 H₂ (g) using Hess’ Law. a. N₂ (g) + 3 H₂ (g) → 2 NH₃ (g)  b. C(s) + 2 H₂ (g) → CH₄ (g)                   c. H₂ (g) + 2 C(s) + N₂ (g) → 2 HCN (g)  d. H₂ (g) + 1/2 O₂ (g) → H₂O (l)

Calculate the ∆H (kJ) of the reaction per mole of lead (II) nitrate consumed (here you must use a negative sign if the process is exothermic). 

What is the best reason for why either Kelvins or degrees Celsius could be used in calorimetry problems.

Which +2 ion has the same configuration?