Nokea
What element has the atomic number 17?
- A. Chlorine (Cl)
- B. Nitrogen (N)
- C. Sodium (Na)
- D. Fluorine (F)
Correct Answer: A
Rationale: The correct answer is Chlorine (Cl). The atomic number of an element corresponds to the number of protons in its nucleus. Chlorine has an atomic number of 17, indicating it has 17 protons. Therefore, the element with atomic number 17 is Chlorine (Cl). Choice B, Nitrogen (N), has an atomic number of 7, Choice C, Sodium (Na), has an atomic number of 11, and Choice D, Fluorine (F), has an atomic number of 9. These elements do not match the atomic number 17, making them incorrect choices.
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What property of a substance refers to its ability to be drawn into thin wires without breaking?
- A. Malleability
- B. Viscosity
- C. Ductility
- D. Conductivity
Correct Answer: C
Rationale: Ductility is the property that allows a substance to be drawn into thin wires without breaking. Malleability, on the other hand, is the ability to be hammered or rolled into thin sheets. Viscosity is the measure of a fluid's resistance to flow. Conductivity, lastly, refers to a substance's ability to conduct electricity or heat. Therefore, in this context, the correct answer is ductility as it specifically relates to the ability of a substance to be drawn into thin wires without breaking.
Which structure allows for the selective passage of materials into and out of the cell?
- A. DNA
- B. Protein
- C. Carbohydrate
- D. Phospholipid bilayer
Correct Answer: D
Rationale: The phospholipid bilayer is a crucial component of the cell membrane, surrounding the cell and regulating the passage of materials into and out of the cell. Its structure enables it to be selectively permeable, controlling which substances can pass through. DNA, proteins, and carbohydrates are essential molecules in the cell but do not directly govern the passage of materials like the phospholipid bilayer does. Therefore, the correct answer is the phospholipid bilayer.
Why does a prism separate white light into its constituent spectral components?
- A. It absorbs certain colors
- B. Different colors experience varying speeds within the prism
- C. It bends all colors with the same magnitude
- D. It reflects specific colors
Correct Answer: B
Rationale: A prism separates white light into its constituent spectral components because different colors experience varying speeds within the prism due to their different wavelengths. This causes the light to refract at different angles, resulting in the separation of colors. When light enters the prism, it undergoes dispersion, where different colors are refracted at different angles due to their unique wavelengths. This phenomenon is known as chromatic dispersion. Choice A is incorrect because a prism does not absorb colors but refracts and disperses them. Choice C is incorrect because a prism refracts different colors at different angles, not with the same magnitude. Choice D is incorrect because a prism does not reflect colors but refracts and disperses them based on their wavelengths.
During ejaculation, sperm travels through a tube from the testes to the urethra. What is the name of this tube?
- A. Vas deferens
- B. Epididymis
- C. Seminal vesicle
- D. Urethra
Correct Answer: A
Rationale: The vas deferens is the correct answer. It is the tube that carries sperm from the testes to the urethra during ejaculation. The vas deferens plays a crucial role in transporting mature sperm for ejaculation. The epididymis is responsible for sperm maturation and storage, not the direct passage of sperm to the urethra. The seminal vesicle produces fluid that combines with sperm to form semen but is not the tube for sperm transport. The urethra serves as the passageway for both urine and semen out of the body but is not the specific tube that transports sperm from the testes to the urethra.
When two coherent light waves with a slight phase difference interfere, what determines the resulting intensity of the combined wave?
- A. The individual intensities of the waves
- B. The wavelength of the waves
- C. The distance between the waves
- D. The color of the waves
Correct Answer: A
Rationale: The resulting intensity of the combined wave is determined by the individual intensities of the waves. When two coherent light waves interfere, the amplitudes of the waves add up, and the resulting intensity is proportional to the square of the sum of the individual amplitudes. Therefore, the individual intensities of the waves play a crucial role in determining the resulting intensity of the combined wave. Choices B, C, and D are incorrect. The wavelength of the waves and the distance between the waves do affect interference patterns but not the resulting intensity. The color of the waves is determined by the wavelength and does not directly determine the resulting intensity of the combined wave.