For which of the following reasons does a chloride ion have a negative charge?
A. It gained an electron
B. It lost an electron.
C. It lost a proton.
D. It gained a proton.
A chloride ion has a negative charge because it gained an electron. When an atom gains an electron, it becomes negatively charged because it now has more electrons than protons. In the case of a chloride ion, the neutral chlorine atom gains an electron to become a negatively charged chloride ion.
The other options are incorrect because they do not result in a negative charge. Losing an electron would result in a positive charge. Losing or gaining a proton would change the identity of the atom and is not related to the formation of a chloride ion.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: Use the table below to answer the question. Object Mass (g) Time of fall (sec) 1 5.0 2.0 2 5.0 1.0 3 30.0 0.5 4 35.0 1.5 Which of the following conclusions is supported by the data?
A. Objects A and B will fall at the same rate.
B. The greater the mass of an object, the faster it will fall.
C. The time of fall is independent of the mass of the object.
D. Air resistance could be greater for A than for B.
Answer Explanation
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Q #2: Genetic information describing the characteristics of an organism is found in which of the following?
A. Nuclei
B. Membranes
C. Cilia
D. Ribosomes
Answer Explanation
The correct answer is a. Nuclei. Genetic information describing the characteristics of an organism is found in the nuclei of its cells. The nucleus contains the organism's DNA, which carries the genetic information that determines its traits.
b. Membranes are structures that surround and enclose cells and organelles, but they do not contain genetic information.
c. Cilia are hair-like structures that protrude from the surface of some cells and are involved in movement, but they do not contain genetic information.
d. Ribosomes are organelles that are involved in protein synthesis, but they do not contain genetic information.
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Q #3: Which of the following describes a genetic mutation that results in uncontrolled division of a single cell within the body?
A. Cancer
B. Gene therapy
C. Stem cell
D. Translation
Answer Explanation
A genetic mutation that results in uncontrolled division of a single cell within the body describes cancer ¹. Cancer is a disease of uncontrolled cell division ¹. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators ¹. In most cases, these changes in activity are due to mutations in the genes that encode cell cycle regulator proteins ¹.
The other options are not correct because they do not accurately describe a genetic mutation that results in uncontrolled division of a single cell within the body. Gene therapy, stem cells, and translation are not processes that result in uncontrolled cell division.
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Q #4: Which of the following is an efferent neuron that is responsible for releasing a neurotransmiter that stimulates a muscle cell to contract?
A. Motor neuron
B. Interneuron
C. Sensory neuron
D. Neuroglia
Answer Explanation
An efferent neuron that is responsible for releasing a neurotransmitter that stimulates a muscle cell to contract is a motor neuron ². Motor neurons carry signals from the brain to the peripheral nervous system in order to initiate an action. The neurotransmitter acetylcholine (ACh) is released by motor neurons at the neuromuscular junction in skeletal muscle, causing the muscle to contract ³.
The other options are incorrect because they do not accurately describe the type of neuron responsible for releasing a neurotransmitter that stimulates a muscle cell to contract. Interneurons are found within the central nervous system and facilitate communication between sensory and motor neurons. Sensory neurons carry information from sensory receptors to the central nervous system. Neuroglia are support cells for neurons and do not transmit nerve impulses.
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Q #5: For which of the following reasons does a chloride ion have a negative charge?
A. It gained an electron
B. It lost an electron.
C. It lost a proton.
D. It gained a proton.
Answer Explanation
A chloride ion has a negative charge because it gained an electron. When an atom gains an electron, it becomes negatively charged because it now has more electrons than protons. In the case of a chloride ion, the neutral chlorine atom gains an electron to become a negatively charged chloride ion.
The other options are incorrect because they do not result in a negative charge. Losing an electron would result in a positive charge. Losing or gaining a proton would change the identity of the atom and is not related to the formation of a chloride ion.
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Q #6: Experiments cannot validate hypotheses, only falsify them. The statement above can be restated in which of the following ways?
A. a. Until disproved, an explanation for an observation is valid.
B. b. Certain concepts cannot be subjected to direct experimentation.
C. c. A hypothesis that has not been falsified remains provisional.
D. d. Proving a hypothesis exempts it from further testing
Answer Explanation
The statement "Experiments cannot validate hypotheses, only falsify them" can be restated as "A hypothesis that has not been falsified remains provisional." This means that a hypothesis is considered valid until it is disproved by experimental evidence. However, even if a hypothesis has not been falsified, it is still considered provisional and subject to further testing and scrutiny.
a."Until disproved, an explanation for an observation is valid" is similar to the correct answer but does not capture the provisional nature of a hypothesis.
b."Certain concepts cannot be subjected to direct experimentation" is not a restatement of the original statement.
d. "Proving a hypothesis exempts it from further testing" is incorrect because no hypothesis can be definitively proven and all hypotheses are subject to further testing and scrutiny.
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Q #7: Which of the following properties does soap, an emulsifier, have that make it useful for washing dirt off one’s hands with water?
A. Soap’s dual polar and nonpolar nature helps bond oil and water
B. Soap’s acidity causes grime to precipitate into the water
C. Soap’s enzymatic action helps to dissolve grime into small particles
D. Soap’s rough texture physically scours grime off surfaces
Answer Explanation
The correct answer is a. Soap’s dual polar and nonpolar nature helps bond oil and water. Soap is an emulsifier, which means that it has both polar and nonpolar regions. The polar regions of soap molecules are atracted to water, while the nonpolar regions are atracted to oil and grease. This allows soap to bond with both water and oil, helping to remove dirt and grime from surfaces.
B. Soap’s acidity does not cause grime to precipitate into the water.
C. Soap does not have enzymatic action that helps to dissolve grime into small particles.
D. Soap’s texture does not physically scour grime off surfaces.
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Q #8: Which of the following terms describes the relaxation of the chambers of the heart during the cardiac cycle?
A. Tachycardia
B. Diastole
C. Systole
D. Bradycardia
Answer Explanation
The relaxation of the chambers of the heart during the cardiac cycle is called diastole ¹. The cardiac cycle is a sequence of events that occurs when the heart beats ². It consists of two phases: systole, when the heart contracts and pumps blood into circulation, and diastole, when the heart relaxes and fills with blood ².
The other options are not correct because they do not accurately describe the relaxation of the chambers of the heart during the cardiac cycle. Tachycardia is a rapid heart rate, bradycardia is a slow heart rate, and systole is the contraction of the heart chambers.
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Q #9: A researcher wants to gather data on the average wing strength of all birds found in the American Northwest. The researcher only has one small net, so all large birds were excluded from the study. The researcher's results were different than expected, but he believes his data include enough birds to estimate the strength of all birds. For which of the following reasons should this data be rejected?
A. Data contradict the control group
B. Data were different than expected
C. Data are biased by the methodology
D. Data cannot be displayed graphically
Answer Explanation
The correct answer is c. Data are biased by the methodology. The researcher's data should be rejected because they are biased by the methodology used to gather them. By only using a small net, the researcher excluded all large birds from the study. This means that the data do not accurately represent the average wing strength of all birds found in the American Northwest.
A. The data contradicting the control group is not a reason to reject the data in this case.
B. The data being different than expected is not a reason to reject the data in this case.
D. The data not being able to be displayed graphically is not a reason to reject the data in this case.
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Q #10: Which of the following classes of biological molecules includes enzymes?
A. Lipids
B. Vitamins
C. Carbohydrates
D. Proteins
Answer Explanation
Enzymes are a type of protein that catalyze chemical reactions in the body. Proteins are one of the four main classes of biological molecules, along with lipids, carbohydrates, and nucleic acids.
The other options are not classes of biological molecules that include enzymes. Lipids are a class of molecules that includes fats and oils, vitamins are organic compounds that are essential for normal growth and nutrition, and carbohydrates are a class of molecules that includes sugars and starches.
