explain the law of conservation of mass as it applies to this reaction 2h o 2h o 2 2

ATI TEAS 7

ATI TEAS Science Practice Test

1. How does the Law of Conservation of Mass apply to this reaction: 2H₂ + O₂ → 2H₂O?

A. Electrons are not lost.
B. The hydrogen does not lose mass.
C. New water molecules are formed.
D. There is no decrease or increase in matter.

Correct answer: D

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction. In the given reaction, 2 moles of hydrogen combine with 1 mole of oxygen to form 2 moles of water. The total mass of the reactants (hydrogen and oxygen) is equal to the total mass of the products (water), meaning there is no decrease or increase in matter. The total mass of the system remains constant, demonstrating the conservation of mass. Choices A, B, and C are incorrect because the conservation of mass does not specifically relate to electrons, individual elements (like hydrogen), or the formation of new molecules; instead, it focuses on the overall mass of the system before and after the reaction.

2. What is a secondary argument the author makes?

A. Devices such as the iPad or Kindle are better than books because they have multiple uses.
B. Books are still important to have while waiting for an appointment or taking a flight.
C. Printed encyclopedias are still used and more convenient than using the Internet.
D. With technology, there will soon be no need for stories.

Correct answer: A

Rationale: The secondary argument made by the author is that devices such as the iPad and Kindle are superior to printed books because they offer multiple functions beyond just reading. The author mentions that these devices have qualities similar to a computer and can be used for much more than just reading, making them a more versatile option compared to traditional books. Choice B is incorrect because the author does not emphasize the importance of books for specific situations like waiting for appointments or flights. Choice C is incorrect as the author does not compare printed encyclopedias to the Internet. Choice D is incorrect as the author does not suggest that technology will eliminate the need for stories; instead, they focus on the transition from printed books to electronic devices for reading.

3. Which of the following is an example of a correctly punctuated sentence?

A. Beatrice is very intelligent; however, she just does not apply herself well enough in her classes to make good grades.
B. Beatrice is very intelligent: she just does not apply herself well enough in her classes to make good grades.
C. Beatrice is very intelligent; she just does not apply herself well enough in her classes to make good grades.
D. Beatrice is very intelligent; she just does not apply herself well enough in her classes to make good grades.

Correct answer: D

Rationale: Option D is the correct answer as it uses a semicolon to correctly separate two independent clauses. In this sentence, 'Beatrice is very intelligent' and 'she just does not apply herself well enough in her classes to make good grades' are two independent clauses that are related but can stand alone as separate sentences. The semicolon is the appropriate punctuation mark to link these two closely related ideas. Choices A, B, and C are incorrect because they either use a comma splice (A), a colon (B), or lack appropriate punctuation (C) to separate the independent clauses.

4. What ethical considerations are associated with the potential use of CRISPR-Cas9 technology in humans?

A. Concerns about unintended consequences on the genome and potential off-target effects.
B. Debates on modifying the human germline and potential eugenic implications.
C. Accessibility and affordability of the technology, ensuring equitable access to benefits.
D. Risks associated with CRISPR-Cas9 editing germline cells and potential long-term impacts.

Correct answer: B

Rationale: The correct answer is B. CRISPR-Cas9 technology allows precise editing of germline cells, raising ethical concerns about modifying the human gene pool. This includes potential eugenic implications, debates on altering future generations, and the moral implications of such genetic modifications. Choice A discusses unintended consequences and off-target effects, but the primary ethical consideration with CRISPR-Cas9 technology relates to altering the human germline. Choices C and D, while important factors, are not the central ethical dilemmas associated with using CRISPR-Cas9 technology in humans.

5. How can a concave mirror be used?

A. Focus light to a single point
B. Create only virtual images
C. Always magnify objects
D. Scatter light

Correct answer: A

Rationale: A concave mirror can be used to focus light to a single point. This property is known as converging light rays to a focal point. When light rays parallel to the principal axis strike a concave mirror, they converge at a specific point called the focal point. This ability to focus light makes concave mirrors useful in applications such as reflecting telescopes and shaving mirrors. Choice B is incorrect because concave mirrors can create both real and virtual images, depending on the object's position relative to the mirror. Choice C is incorrect as concave mirrors can magnify, reduce, or maintain the size of objects, depending on the object's position and the distance from the mirror. Choice D is incorrect as concave mirrors do not scatter light but instead have the ability to reflect and focus light to produce clear images.