Major components of organic compounds such as fats, phospholipids and fossil fuels consist of hydrocarbons. Hydrocarbons are molecules that are made of
A. hydrogen and carbon atoms.
B. hydrogen, oxygen and carbon atoms.
C. water molecules and carbon atoms.
D. hydrogen, carbon and nitrogen atoms.
查看答案
Which of the following is the correct functional group for alcohols?
A. -COOH
B. -CH3
C. -OH
D. -SH
Isomers have the ____ chemical formula, _____ chemical structures and _____ biological functions.
A. different, different, same
B. same, different, different
C. same, different, same
D. different, same, same
Carbon can form up to four covalent bonds because --
A. it has four valence electrons.
B. it is a polar molecule.
C. it bonds to hydrogens, which are small.
D. it has a greater electronegativity than most other elements.
Which statement best describes hydrogen bonding?
A. a covalent bond that occurs when an negatively charged oxygen donates an electron to a positively charged hydrogen
B. an ionic bond that occurs when a hydrogen shares its lone electron with an oxygen or nitrogen
C. an attactive force between the partial positive charge on a hydrogen and a partial negative charge on an oxygen or nitrogen
D. an attactive force between the partial negative charge on a hydrogen and a partial positive charge on an oxygen or nitrogen
微信支付 
支付宝支付