46. A deuteron has the same charge as a proton (qd = qp), but twice the mass (md =2mp). Both particles move in circular paths in a plane perpendicular to a uniform magnetic field. The radius of the deuteron's circular path is twice that of the proton (rd= 2rp). Which of the following statements is correct? (A) The relation between their angular momentum Ld/Lp is 2. (B) The relation between their acceleration is ad/ap is 2. (C) The relation between their angular speed is ωd/ωp =2. (D) The relation between their tangential speed is vd/vp is 2. (E) The relation between their period of the circular motion is Td/Tp is 2.

6. The basic building blocks of nucleic acids HC are nucleotides. The figure on the right shows a fragment of a nucleic acid structure. Which of the following statements is NOT correct? (A) DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) contain the same nitrogenous bases, but their five-carbon sugars are different. H 0 -O -CH OH (B) A nitrogenous base condenses with a five-carbon sugar to form anucleoside; a nucleoside condenses with phosphoric acid to form a nucleotide; nucleotides undergo condensation polymerization to form a nucleic acid. (C) Under certain conditions, a nucleotide can react with both acids and bases. (D) In nucleic acid molecules, bases undergo complementary pairing through hydrogen bonding. (E) This nucleic acid fragment contains three chiral centers.

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