TEAS 7 practice test free science

Correct Answer: A

Rationale: Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. This double bond is a key characteristic that distinguishes alkenes from other types of hydrocarbons. Option A correctly identifies this defining feature of alkenes, making it the correct answer. Choices B, C, and D are incorrect. Choice B is incorrect because alkenes are unsaturated hydrocarbons due to the presence of double bonds. Choice C is incorrect as alkenes do not contain only single bonds; they have at least one double bond. Choice D is incorrect because alkenes are not derivatives of ammonia; they are a distinct class of organic compounds with carbon-carbon double bonds.

Correct Answer: B

Rationale: Immunosuppressive drugs work by suppressing the immune system's activity, which can increase the risk of infections as the body's ability to fight off pathogens is compromised. While allergies can be a side effect of some medications, the primary concern with immunosuppressive drugs is the increased susceptibility to infections. Therefore, the correct answer is B, increased susceptibility to infections. Choice A, 'Increased risk of developing allergies,' is incorrect as the primary risk associated with immunosuppressive drugs is not related to allergies. Choice C, 'Both A and B,' is incorrect as the main concern is the increased susceptibility to infections rather than developing allergies. Choice D, 'Neither A nor B,' is incorrect as there is a known risk of increased susceptibility to infections when using immunosuppressive drugs.

Correct Answer: B

Rationale: The recommended daily fluid intake for adults is typically around 2 liters, which is equivalent to about 8 cups or half a gallon. This amount can vary depending on factors such as age, gender, weight, activity level, and climate. Staying adequately hydrated is essential for overall health and helps maintain proper bodily functions, such as regulating body temperature, aiding digestion, and transporting nutrients and oxygen throughout the body. Drinking enough fluids also helps prevent dehydration, which can lead to symptoms like fatigue, headaches, and dizziness. Choice A, 1 liter, is insufficient and may not meet the body's hydration needs, while choices C and D, 3 liters and 4 liters, respectively, are excessive for most adults and could potentially lead to overhydration, which may have negative health consequences. It's important to note that individual fluid needs may vary, so it's always best to consult with a healthcare provider for personalized recommendations.

Correct Answer: C

Rationale: The correct answer is C, Frequency. The energy of a wave is determined by its frequency, not its amplitude, wavelength, or velocity. According to the equation E = h*f, where E is energy, h is Planck's constant, and f is frequency, the energy of a wave is directly proportional to its frequency. Higher frequency waves carry more energy, while lower frequency waves carry less energy. Therefore, frequency plays a crucial role in determining the energy content of a wave, making it the correct choice in this context.

Correct Answer: B

Rationale: Elements within the same group share similar electron configurations in their outermost shell. The periodic table is organized based on the number of electrons in the outermost energy level, known as valence electrons, which significantly influence an element's chemical properties. Elements within the same group have the same number of valence electrons, leading to comparable chemical behaviors. Choices A and D are incorrect because elements within the same period, not group, have identical electron configurations, and an element's group is primarily determined by the number of valence electrons and not the number of electron shells. Choice C is incorrect because while electron configuration is crucial for understanding an element's properties, it is not the sole factor determining its position on the periodic table.