What is the difference between a physical change and a chemical change?
A. A physical change involves the rearrangement of atoms and molecules while a chemical change involves the formation of new substances with different chemical properties.
B. A physical change involves the change of one state of mater to another while a chemical change involves the change of one substance into another.
C. A physical change involves the breaking of chemical bonds while a chemical change involves the breaking of intermolecular forces.
D. A physical change involves the release of energy while a chemical change involves the absorption of energy.
A physical change is a change that affects the physical properties of a substance, but does not change its chemical identity. Physical changes include changes in state, such as melting or boiling, changes in shape or size, and changes in phase, such as the dissolution of a solid in a liquid. In a physical change, the atoms and molecules of the substance are rearranged, but no new substances are formed.
A chemical change, on the other hand, is a change that results in the formation of new substances with different chemical properties. Chemical changes involve the breaking of chemical bonds between atoms and the formation of new bonds to create new compounds. Chemical changes are usually accompanied by a change in color, the formation of a gas or a solid, or the release or absorption of energy.
Overall, the main difference between a physical change and a chemical change is that a physical change only affects the physical properties of a substance while a chemical change results in the formation of new substances with different chemical properties.
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Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: What is the role of the epididymis in sperm maturation?
A. The epididymis produces sperm cells.
B. The epididymis stores and protects sperm cells until ejaculation.
C. The epididymis is responsible for the transport of sperm cells from the testes to the urethra.
D. The epididymis provides nourishment to sperm cells.
Answer Explanation
The epididymis is a coiled tube located at the back of each testicle where the sperm mature and are stored until ejaculation. Sperm are produced in the testes and then transported to the epididymis where they undergo maturation and become motile. The epididymis provides a protective environment for the sperm, allowing them to mature and become more resilient to external stressors. During ejaculation, the sperm are transported from the epididymis to the vas deferens and then to the urethra for ejaculation.
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Q #2: What are the five regions of the vertebral column, starting from the top and moving downwards?
A. Cervical, thoracic, lumbar, sacral, coccygeal
B. Thoracic, cervical, lumbar, sacral, coccygeal
C. Lumbar, thoracic, cervical, coccygeal, sacral
D. Sacral, lumbar, cervical, thoracic, coccygeal
Answer Explanation
The vertebral column, also known as the spine or spinal column, is a series of bones called vertebrae that extend from the skull to the pelvis. It provides support for the body and protects the spinal cord. The five regions of the vertebral column, starting from the top and moving downwards, are:
- Cervical: This region is made up of seven vertebrae and is located in the neck. The first two cervical vertebrae, the atlas and the axis, are specialized to allow for head movement.
- Thoracic: This region is made up of twelve vertebrae and is located in the upper and middle back. The thoracic vertebrae are larger than the cervical vertebrae and articulate with the ribs.
- Lumbar: This region is made up of five vertebrae and is located in the lower back. The lumbar vertebrae are the largest and strongest of the vertebrae.
- Sacral: This region is made up of five fused vertebrae and is located in the pelvis. The sacrum forms the posterior wall of the pelvis and articulates with the hip bones.
- Coccygeal: This region is made up of four fused vertebrae and is located at the base of the vertebral column. The coccyx, or tailbone, provides atachment points for muscles and ligaments.
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Q #3: What are the three types of salivary glands and where are they located in the mouth?
A. Parotid, sublingual, and submandibular glands located in the cheeks, tongue, and roof of the mouth, respectively.
B. Sublingual, submandibular, and buccal glands located in the tongue, cheeks, and lips, respectively.
C. Parotid, sublingual, and submandibular glands located in the roof of the mouth, cheeks, and under the jawbone, respectively.
D. Sublingual, parotid, and buccal glands located in the tongue, cheeks, and lips, respectively.
Answer Explanation
The three major pairs of salivary glands are the parotid glands, sublingual glands, and submandibular glands.
- Parotid glands are located just in front of your ears.
- Sublingual glands are located below either side of your tongue, under the floor of your mouth.
- Submandibular glands are located below your jaw.
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Q #4: Which of the following is an example of a double-blind study?
A. Participants are randomly assigned to a treatment group or a control group
B. Participants and researchers both know which group participants are assigned to
C. Participants do not know which group they are assigned to, but researchers do
D. Both participants and researchers do not know which group participants are assigned to
Answer Explanation
A double-blind study is a research design in which neither the participants nor the researchers know which group participants are assigned to. This is done to minimize bias and ensure that the results of the study are as objective as possible. In a double-blind study, the treatment and control groups are randomly assigned, and the participants and researchers are unaware of which group each participant is assigned to. Option a) is an example of a randomized controlled trial, which is a common research design, but it is not necessarily double-blind. Option b) is an example of an open-label study, in which both the participants and the researchers know which group each participant is assigned to. Option c) is an example of a single-blind study, in which the participants do not know which group they are assigned to, but the researchers do.
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Q #5: During embryonic development, which of the following germ layers forms the nervous system?
A. Ectoderm
B. Endoderm
C. Mesoderm
D. Exoderm
Answer Explanation
The three germ layers that form during embryonic development are the ectoderm, mesoderm, and endoderm. The ectoderm is the outermost layer, and it gives rise to the skin, hair, nails, and nervous system. The nervous system develops from a specialized region of the ectoderm called the neural plate, which invaginates to form the neural tube. The neural tube ultimately gives rise to the brain and spinal cord, which make up the central nervous system, as well as the peripheral nervous system. The endoderm gives rise to the lining of the digestive and respiratory tracts, while the mesoderm gives rise to the musculoskeletal system, circulatory system, and several other organs. The exoderm is not a germ layer and does not exist during embryonic development.
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Q #6: What is the name of the joint that allows for rotation of the arm at the shoulder?
A. Elbow joint
B. Hip joint
C. Knee joint
D. Shoulder joint
Answer Explanation
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Q #7: What is the difference between a physical change and a chemical change?
A. A physical change involves the rearrangement of atoms and molecules while a chemical change involves the formation of new substances with different chemical properties.
B. A physical change involves the change of one state of mater to another while a chemical change involves the change of one substance into another.
C. A physical change involves the breaking of chemical bonds while a chemical change involves the breaking of intermolecular forces.
D. A physical change involves the release of energy while a chemical change involves the absorption of energy.
Answer Explanation
A physical change is a change that affects the physical properties of a substance, but does not change its chemical identity. Physical changes include changes in state, such as melting or boiling, changes in shape or size, and changes in phase, such as the dissolution of a solid in a liquid. In a physical change, the atoms and molecules of the substance are rearranged, but no new substances are formed.
A chemical change, on the other hand, is a change that results in the formation of new substances with different chemical properties. Chemical changes involve the breaking of chemical bonds between atoms and the formation of new bonds to create new compounds. Chemical changes are usually accompanied by a change in color, the formation of a gas or a solid, or the release or absorption of energy.
Overall, the main difference between a physical change and a chemical change is that a physical change only affects the physical properties of a substance while a chemical change results in the formation of new substances with different chemical properties.
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Q #8: Which of the following substances is excreted by the kidneys to regulate blood pressure?
A. renin
B. erythropoietin
C. calcitriol
D. urobilinogen
Answer Explanation
Renin is an enzyme that is produced by the kidneys and it acts to elevate blood pressure. When blood pressure falls, the kidneys secrete renin into the bloodstream ³.
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Q #9: What are the steps involved in the scientific method?
A. Observation, hypothesis, prediction, experimentation, analysis, conclusion.
B. Hypothesis, observation, prediction, experimentation, analysis, conclusion.
C. Prediction, observation, experimentation, analysis, conclusion, hypothesis.
D. Observation, data collection, analysis, experimentation, hypothesis, conclusion.
Answer Explanation
The scientific method is a systematic approach used to answer questions or test hypotheses about the natural world. The steps involved in the scientific method are:
- Observation: This is the first step in the scientific method. It involves observing a phenomenon or a problem and gathering information about it.
- Hypothesis: After making an observation, a scientist forms a hypothesis, which is a tentative explanation for the phenomenon or problem.
- Prediction: Based on the hypothesis, the scientist makes a prediction about what will happen in an experiment or what they will observe.
- Experimentation: The scientist designs and conducts an experiment to test the hypothesis and prediction.
- Analysis: The data collected from the experiment are analyzed to determine if they support or refute the hypothesis.
- Conclusion: Based on the analysis of the data, the scientist draws a conclusion about whether the hypothesis is supported or refuted.
Option b) is incorrect because it starts with hypothesis before observation. Option c) is incorrect because prediction comes before experimentation. Option d) is incorrect because hypothesis comes after observation and data collection.
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Q #10: Which of the following statements is true regarding vaccines?
A. Vaccines can cause the disease they are designed to protect against
B. Vaccines work by providing passive immunity to the individual
C. Vaccines work by exposing the individual to a weakened or inactivated form of the pathogen
D. Vaccines only provide protection against bacterial infections
Answer Explanation
Vaccines are a type of preventative medicine that work by exposing the individual to a weakened or inactivated form of a pathogen (such as a virus or bacteria) or to a piece of the pathogen (such as a protein or sugar) that triggers an immune response in the body. This exposure allows the body to develop immunity to the pathogen without getting sick from the full-blown disease. Once the immune system has been primed, it can recognize and quickly respond to the pathogen if it is encountered again in the future, providing protection against the disease.
It is a common misconception that vaccines can cause the disease they are designed to protect against. This is not true. While some vaccines may cause mild symptoms such as a low-grade fever or soreness at the injection site, they do not cause the full-blown disease.
Vaccines provide active immunity, meaning that the body produces its own antibodies against the pathogen, rather than receiving pre-made antibodies as in passive immunity. Additionally, vaccines can be effective against both bacterial and viral infections, depending on the specific vaccine.
