when magnesium metal reacts with hydrochloric acid hydrogen gas is produced what evidence suggests a chemical reaction is occurring
Logo

Nursing Elites

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. When magnesium metal reacts with hydrochloric acid, hydrogen gas is produced. What evidence suggests a chemical reaction is occurring?

Correct answer: B

Rationale: The formation of a gas is evidence of a chemical reaction occurring. In this case, when magnesium metal reacts with hydrochloric acid, hydrogen gas is produced, indicating a chemical change is taking place. The production of gas is a clear indication of a chemical reaction, as new substances are being formed. A change in color might suggest a physical change, dissolving in a liquid could be a physical or chemical change depending on the context, and no change in temperature does not necessarily indicate a chemical reaction, as some reactions are endothermic or release small amounts of heat that may not be easily noticeable.

2. Molecular clocks utilize the accumulation of mutations in DNA sequences to estimate the evolutionary divergence time between species. This method relies on the assumption that:

Correct answer: A

Rationale: A molecular clock is a method used to estimate the time of divergence between species by measuring the accumulation of mutations in DNA sequences. This method relies on the assumption that mutations occur at a relatively constant rate over time. If the rate of mutation were not constant, it would be challenging to accurately estimate the evolutionary divergence time between species. Therefore, option A is the most appropriate choice as it aligns with the fundamental principle underlying the molecular clock hypothesis. Option B is incorrect because the assumption that species with more morphological similarities diverged more recently does not directly relate to the concept of molecular clocks and the accumulation of mutations in DNA sequences. Option C is incorrect because mutations are not always beneficial and do not always contribute to increased fitness. Mutations can be neutral or deleterious as well, and their accumulation is what is used to estimate evolutionary di

3. Elements tend to gain or lose electrons to achieve stable electron configurations like those of noble gases. Their group number often indicates the number of electrons gained/lost and the resulting ionic charge, providing a good starting point for prediction.

Correct answer: C

Rationale: Ionic bonds typically form between metals and non-metals, where one atom donates electrons (cation) and the other accepts electrons (anion). This results in the transfer of electrons. Metallic bonds, on the other hand, occur between metal atoms where electrons are shared among a sea of delocalized electrons, leading to the characteristic properties of metals like malleability and conductivity. Choice A is incorrect because ionic bonds involve electron transfer, not sharing. Choice B is incorrect as ionic bonds are strong, not weak, and are non-directional, while metallic bonds are strong and non-directional. Choice D is incorrect as ionic bonds do not form discrete molecules but rather a lattice structure, whereas metallic bonds form extended structures.

4. What are isotopes?

Correct answer: B

Rationale: Isotopes are atoms of the same element with different numbers of neutrons. While isotopes share the same number of protons, which determines the element, they differ in the number of neutrons. This variance in neutron count results in isotopes having different atomic masses. Choice A is incorrect because isotopes have the same number of protons (same element) but differ in the number of neutrons. Choice C is incorrect as it describes atoms of different elements, not isotopes of the same element. Choice D is also incorrect because isotopes can have different numbers of electrons, but what defines isotopes is the variation in neutron numbers.

5. How are the bones of the skull classified?

Correct answer: C

Rationale: The bones of the skull are classified as flat bones. Flat bones are thin, flattened, and usually curved bones that provide protection to underlying organs and have a large surface area for muscle attachment. The skull bones fit this description as they protect the brain and have a broad surface for muscle attachment. Choice A (Long bones), B (Short bones), and D (Irregular bones) are incorrect classifications. Long bones are typically found in the extremities like the arms and legs, short bones are cube-shaped like the wrist and ankle bones, and irregular bones have complex shapes like the vertebrae. These classifications do not describe the bones of the skull, which are predominantly flat bones.

Similar Questions

What is the primary function of ribosomes in a cell?
What controls the involuntary, rhythmic contractions of the heart muscle?
What is the formula for calculating density?
Which of the following is an example of a secondary alcohol?
Which of the following lobes in the cerebral cortex is primarily responsible for processing and integrating sensory information received from the rest of the body?

Access More Features

ATI TEAS Premium Plus
$149.99/ 90 days

  • Actual ATI TEAS 7 Questions
  • 3,000 questions with answers
  • 90 days access

ATI TEAS Basic
$99/ 30 days

  • 3,000 Questions with answers
  • 30 days access

Other Courses