ati teas 7 science

Correct Answer: B

Rationale: The correct answer is B. A decomposition reaction involves a single compound breaking down into two or more simpler substances. In choice B, CaCO3 decomposes into CaO and CO2. This reaction follows the general form AB → A + B, making it a clear example of a decomposition reaction. Choices A, C, and D involve synthesis or combination reactions, where simpler substances combine to form a more complex compound, making them incorrect for this question.

Correct Answer: B

Rationale: The correct answer is B: 2H2 + O2 → 2H2O. This equation is balanced because there are equal numbers of each type of atom on both sides of the equation. Balancing involves adjusting the coefficients to ensure the conservation of mass. In this case, there are 2 hydrogen atoms on each side and 2 oxygen atoms on each side, making it balanced. Explanation for other choices: A: H2 + O2 → H2O - Not balanced, as there are 2 hydrogen atoms on the left but only 1 on the right. C: 3H2O → 2H2 + O2 - Not balanced, as there are 6 hydrogen atoms on the left but only 2 on the right. D: H2O → H2 + O2 - Not balanced, as there are 1 oxygen atom on the left but 2 on the right.

Correct Answer: B

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: C

Rationale: The correct answer is C: Vitamin D. When the skin is exposed to sunlight, a form of cholesterol in the skin is converted into Vitamin D. This vitamin plays a crucial role in calcium absorption and bone health. Vitamin A is not synthesized in the skin but obtained through diet. Vitamin C is obtained from fruits and vegetables. Vitamin E is a fat-soluble vitamin found in nuts and seeds. In summary, only Vitamin D is synthesized in the skin upon sunlight exposure, making it the correct answer.

Correct Answer: A

Rationale: The correct answer is A: Meters per second. The speed of light in a vacuum is a measure of how fast light travels, which is approximately 299,792,458 meters per second. This unit is commonly used in physics to quantify the speed of light. Hertz (B) is a unit of frequency, Candela (C) is a unit of luminous intensity, and Newton (D) is a unit of force, not speed. Therefore, A is the correct unit to measure the speed of light in a vacuum.