What is hydrogen bonding?
A. The attraction between the relatively positive areas of one molecule and the relatively negative areas of another molecule.
B. The repulsion between the positive and negative charges of two molecules.
C. The attraction between two nonpolar molecules.
D. The attraction between two ionic molecules.
Hydrogen bonding is an interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons.
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One atom of the pair (the donor), generally a fluorine, nitrogen, or oxygen atom, is covalently bonded to a hydrogen atom, whose electrons it shares unequally; its high electron affinity causes the hydrogen to take on a slight positive charge.
The other atom of the pair (the acceptor), also typically F, N, or O, has an unshared electron pair, which gives it a slight negative charge.
Mainly through electrostatic attraction, the donor atom effectively shares its hydrogen with the acceptor atom, forming a bond.
Choice B) The repulsion between the positive and negative charges of two molecules is incorrect because hydrogen bonding involves attraction, not repulsion.
Choice C) The attraction between two nonpolar molecules is incorrect because hydrogen bonding involves polar molecules.
Choice D) The attraction between two ionic molecules is incorrect because hydrogen bonding involves polar molecules and not ionic molecules.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: A patient with chronic renal failure is undergoing hemodialysis. What process allows for the removal of waste products and excess fluid from the patient's bloodstream during hemodialysis?
A. Active transport.
B. Osmosis
C. Diffusion
D. Facilitated diffusion.
Answer Explanation
Diffusion.
During hemodialysis, waste products and excess fluids are removed from the blood by diffusion 1.
Diffusion is a separation process in which particles that are dissolved in a solution are relocated from an area of higher concentration in the blood to an area of lower concentration in the dialysate.
Choice A.
Active transport is incorrect because active transport is a process that uses energy to move molecules against a concentration gradient.
Choice B.
Osmosis is incorrect because osmosis is the movement of water molecules across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration.
Choice D.
Facilitated diffusion is incorrect because facilitated diffusion is a process where molecules move down their concentration gradient with the help of carrier proteins.
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Q #2: What is the relationship between viruses and their host cells during replication?
A. Viruses use the host’s replication processes to produce progeny virus particles.
B. Viruses divide inside the host cell to produce progeny virus particles.
C. Viruses have their own replication processes and do not need the host cell.
D. Viruses infect the host cell and destroy it completely.
Answer Explanation
Viruses use the host’s replication processes to produce progeny virus particles.
Viruses are obligate intracellular parasites, meaning that they require a host cell to replicate.
They hijack the host cell’s machinery to produce new virus particles.
Choice B is incorrect because viruses do not divide inside the host cell.
Instead, they use the host cell’s machinery to produce new virus particles.
Choice C is incorrect because viruses do not have their own replication processes and rely on the host cell for replication.
Choice D is incorrect because while some viruses may destroy the host cell during replication, this is not always the case and is not the primary relationship between viruses and their host cells during replication.
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Q #3: A nurse is conducting a research study to compare the effects of two different pain medications on postoperative patients. The nurse randomly assigns the patients to either receive medication A or medication B. Which of the following is the best way to ensure that the study is valid and reliable?
A. Use a large sample size and a standardized procedure for administering the medications.
B. Use a placebo group and a double-blind technique for giving the medications.
C. Use a matched-pairs design and a crossover technique for switching the medications.
D. Use a convenience sample and a pretest-posttest design for measuring the pain levels.
Answer Explanation
The correct answer is choice B.
Using a placebo group and a double-blind technique for giving the medications is the best way to ensure that the study is valid and reliable.
A placebo group helps control for the placebo effect, which can influence the results of a study.
A double-blind technique means that neither the patients nor the researchers know which medication is being given, reducing bias.
Choice A is not the best answer because while a large sample size and standardized procedure can increase reliability, they do not address validity.
Choice C is not the best answer because a matched-pairs design and crossover technique are useful for reducing variability but do not address validity.
Choice D is not the best answer because a convenience sample may not be representative and a pretest-posttest design does not control for extraneous variables.
