ATI TEAS 7 Science

Correct Answer: C

Rationale: The correct answer is C (2+ or 3+). Iron is a transition metal, meaning it has variable oxidation states. Iron commonly forms cations with charges of 2+ (Fe²⁺) or 3+ (Fe³⁺) due to its ability to lose 2 or 3 electrons, respectively, from its outer shell. This is consistent with the typical behavior of transition metals to exhibit multiple oxidation states. Choices A and B are incorrect because iron does not commonly form cations with charges of 2- or 3-. Choice D is incorrect as iron typically forms cations with a positive charge, not a negative charge.

Correct Answer: B

Rationale: The correct answer is B: Blood pressure. Blood pressure is the term for the pressure exerted by blood against the walls of blood vessels. It is a crucial indicator of cardiovascular health. Heart rate (A) is the number of times the heart beats per minute, not directly related to blood vessel pressure. Cardiac output (C) is the amount of blood pumped by the heart per minute, not the pressure exerted on blood vessel walls. Stroke volume (D) is the volume of blood pumped by the heart in a single contraction, not the pressure against blood vessel walls.

Correct Answer: A

Rationale: The correct answer is A: Covalent bond. In a covalent bond, atoms share electrons to achieve a stable electron configuration. This sharing allows both atoms to fill their outer electron shells and form a strong bond. Ionic bonds (choice B) involve the transfer of electrons, not sharing. Metallic bonds (choice C) occur in metals where electrons are delocalized. Hydrogen bonds (choice D) are weak electrostatic attractions between hydrogen and electronegative atoms, not a result of electron sharing. Thus, the correct answer is A because it accurately describes the sharing of electrons between elements to form a covalent bond.

Correct Answer: B

Rationale: The correct answer is B (25 grams) as the recommended daily fiber intake for adults by the American Heart Association is 25-30 grams. Fiber helps with digestion, heart health, and weight management. Option A (10 grams) is too low and insufficient for daily needs. Option C (35 grams) and D (50 grams) are excessive and may lead to digestive issues like bloating or gas. Therefore, B is the most appropriate choice for optimal health benefits.

Correct Answer: B

Rationale: Insulin is the correct answer as it is responsible for lowering blood sugar levels by promoting the uptake of glucose into cells. Glucagon raises blood sugar levels, adrenaline and cortisol are stress hormones that increase blood sugar levels. Therefore, the correct choice is B.