Nokea
When baking soda (sodium bicarbonate) reacts with vinegar (acetic acid), what type of reaction occurs?
- A. Combustion
- B. Double displacement
- C. Decomposition
- D. Synthesis
Correct Answer: B
Rationale: When baking soda (sodium bicarbonate) reacts with vinegar (acetic acid), a double displacement reaction occurs. In this reaction, the positive ions in baking soda switch places with the positive ions in vinegar to form water, carbon dioxide, and a salt. Combustion involves a reaction with oxygen to produce heat and light energy. Decomposition is the breakdown of a compound into simpler substances, which is not the case in the given reaction. Synthesis is the combination of substances to form a more complex compound, which is also not the type of reaction observed when baking soda and vinegar react.
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Which property of a wave is measured in Hertz (Hz)?
- A. Amplitude
- B. Wavelength
- C. Speed
- D. Frequency
Correct Answer: D
Rationale: Frequency is the property of a wave that is measured in Hertz (Hz). It represents the number of complete cycles of the wave that occur in one second. Amplitude refers to the height of the wave, wavelength is the distance between two consecutive points on a wave that are in phase, and speed is the rate at which the wave travels through a medium. Therefore, the correct answer is frequency as it directly corresponds to the unit Hertz (Hz) used to measure the number of wave cycles per second.
Which condition is commonly associated with frequent, painful urination?
- A. Diabetes
- B. Urinary tract infection (UTI)
- C. Kidney stones
- D. All of the above
Correct Answer: D
Rationale: Frequent, painful urination can be indicative of various conditions. Diabetes may cause increased urination due to high blood sugar levels, UTIs can lead to pain and frequent urination, and kidney stones can also result in painful urination. Therefore, all of the options (A, B, and C) are correct in this scenario, making option D, 'All of the above,' the correct answer. Option D encompasses all the conditions commonly associated with frequent, painful urination, making it the most comprehensive and accurate choice.
A person who carries a pathogen but does not exhibit any symptoms is considered:
- A. Asymptomatic carrier
- B. Opportunistic pathogen
- C. Nosocomial infection
- D. Vector-borne disease
Correct Answer: A
Rationale: An asymptomatic carrier is a person who carries a pathogen, such as a virus or bacterium, without showing any symptoms of the infection. Despite lacking symptoms, asymptomatic carriers can still transmit the pathogen to others, potentially causing illness in those they contact. This term specifically pertains to infected individuals who do not manifest symptoms, distinguishing them from symptomatic carriers who do exhibit signs of the infection. Option A is the most fitting choice as it accurately characterizes a person carrying a pathogen without displaying symptoms.
B) Opportunistic pathogen: This term describes pathogens that typically do not cause disease in healthy individuals but can be pathogenic in those with weakened immune systems.
C) Nosocomial infection: This term refers to infections acquired in a hospital or healthcare facility.
D) Vector-borne disease: This term relates to diseases transmitted to humans by vectors like mosquitoes or ticks.
Which statement correctly describes the concept of ionization energy?
- A. The energy required to remove an electron from an outermost shell.
- B. The energy released when an electron bonds with an atom.
- C. The total energy possessed by all electrons in an atom.
- D. The energy needed to change an atom's nucleus.
Correct Answer: A
Rationale: Ionization energy is defined as the energy required to remove an electron from an atom in the gaseous state. This process typically involves removing an electron from the outermost shell of the atom. Therefore, option A accurately describes the concept of ionization energy. The other choices do not accurately describe ionization energy; option B refers to bond formation energy, option C is about the total energy of electrons in an atom, and option D relates to nuclear energy changes, not ionization energy.
When two cars with different masses collide head-on, which car experiences a greater change in momentum?
- A. The car with the larger mass
- B. The car with the smaller mass
- C. Both cars experience the same change in momentum
- D. It depends on the initial velocities of the cars
Correct Answer: C
Rationale: In a head-on collision between two cars, the law of conservation of momentum states that the total momentum of the isolated system remains constant before and after the collision. The change in momentum of one car is equal in magnitude but opposite in direction to the change in momentum of the other car. As a result, both cars experience the same change in momentum during the collision. Choice A is incorrect because the change in momentum is the same for both cars due to the conservation of momentum principle. Choice B is incorrect as the smaller mass car does not experience a greater change in momentum. Choice D is incorrect as the initial velocities of the cars do not determine which car experiences a greater change in momentum; it is solely dependent on the masses of the colliding cars.