ati teas 7 science

Correct Answer: B

Rationale: The correct answer is B: Protons and neutrons only. Electrons are not found in the nucleus, as they orbit around the nucleus in electron shells. Protons and neutrons are the subatomic particles found within the nucleus of an atom. Protons have a positive charge, while neutrons are neutral. The nucleus contains almost all of the atom's mass and is positively charged due to the presence of protons. Choice A is incorrect because electrons are not part of the nucleus. Choice C is incorrect because electrons are not present in the nucleus. Choice D is incorrect as protons and neutrons are indeed constituents of the atomic nucleus.

Correct Answer: D

Rationale: The correct answer is D: Trachea. The trachea is the largest part of the airway. It is a tube that connects the larynx to the bronchi, allowing air to pass into and out of the lungs. The trachea is larger than the bronchi, bronchioles, and alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Bronchi are the main air passages into the lungs, branching off from the trachea. Bronchioles are smaller branches of the bronchi. Therefore, the trachea is the largest structure among the given choices, making it the correct answer.

Correct Answer: A

Rationale: The P wave on an ECG represents atrial depolarization. During the cardiac cycle, the electrical impulse originates in the sinoatrial (SA) node, causing the atria to contract. This depolarization of the atria is reflected as the P wave on the ECG. This occurs before the ventricles depolarize (choice B), repolarize (choice D), or before the atria repolarize (choice C). Therefore, the correct answer is A because the P wave specifically represents atrial depolarization in the cardiac cycle.

Correct Answer: B

Rationale: The correct answer is B: Ammonia (NH₃). Ammonia is a common base found in household products due to its ability to accept protons and increase the pH of solutions. It is commonly used in cleaning products such as glass cleaners and floor cleaners. A: Sodium chloride (NaCl) is a salt and not a base. C: Vinegar is acidic due to the presence of acetic acid. D: Lemon juice is also acidic due to the presence of citric acid. Therefore, B is the correct answer as it is a common base found in household products, while the other choices are either salts or acidic substances.

Correct Answer: A

Rationale: The correct answer is A: Hydrogen gas and sodium chloride (NaCl). When NaOH reacts with HCl, a neutralization reaction occurs, forming water and a salt. NaOH + HCl -> NaCl + H2O. Sodium chloride and water are the products formed in this reaction. Hydrogen gas is also produced as a byproduct. Choices B, C, and D are incorrect as they do not represent the correct products of the reaction based on the chemical equation.