Question
What are linked by hydrogen bonds?
A. Hydrogen and oxygen within a water molecule
B. Phosphate and sugar within a DNA molecule
C. Base and sugar between DNA nucleotides
D. Hydrogen and oxygen in different water molecules
Answer/Explanation
Ans: D
Question
Between which atoms do hydrogen bonds form in water?
A. Oxygen and hydrogen atoms in the same water molecule
B. Oxygen and hydrogen atoms in different water molecules
C. Hydrogen atoms in the same water molecule
D. Oxygen atoms of different water molecules
▶️Answer/Explanation
Markscheme
Ans: B
Hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atom of another water molecule. Each water molecule can form 2 hydrogen bonds between oxygen and the two hydrogen atoms in the molecule.
Question
What property of water accounts for its usefulness as a coolant in sweat?
High specific heat capacity
High latent heat of vaporization
High boiling point
High melting point
Answer/Explanation
Ans: B