two isotopes of the same element have different numbers of

ATI TEAS 7

ATI TEAS 7 Science Practice Test

1. Two isotopes of the same element have different numbers of:

A. Electrons
B. Protons
C. Neutrons
D. Nuclei

Correct answer: C

Rationale: The correct answer is C: 'Neutrons.' Isotopes are variants of an element that have the same number of protons and electrons but differ in the number of neutrons they contain. This difference in neutron count is what distinguishes isotopes from each other while maintaining the same chemical properties. Choice A, 'Electrons,' is incorrect because isotopes of the same element have the same number of electrons. Choice B, 'Protons,' is incorrect because isotopes of the same element have the same number of protons. Choice D, 'Nuclei,' is incorrect as nuclei refer to the central part of an atom containing protons and neutrons, and the question specifically asks about differences between isotopes of the same element.

2. Which of the following describes how atomic radius varies across the periodic table?

A. Atomic radius increases from top to bottom and left to right on the periodic table.
B. Atomic radius increases from top to bottom and right to left on the periodic table.
C. Atomic radius increases from top to bottom and toward the halogens on the periodic table.
D. Atomic radius increases from top to bottom and toward the noble gases on the periodic table.

Correct answer: A

Rationale: Atomic radius tends to increase from top to bottom and left to right on the periodic table. This is because as you move down a group (top to bottom), new energy levels are added, increasing the distance of the outer electrons from the nucleus and thus increasing the size of the atom. On the other hand, as you move from left to right across a period, the number of protons and electrons increases, leading to a stronger nuclear charge that attracts the electrons closer to the nucleus, resulting in smaller atomic radii. Choice B is incorrect as atomic radius does not increase from right to left. Choices C and D are incorrect as they incorrectly associate the trend with specific groups of elements (halogens and noble gases) rather than the general trend observed on the periodic table.

3. What is the term for the phenomenon when two waves combine to form a new wave?

A. Diffraction
B. Interference
C. Refraction
D. Dispersion

Correct answer: B

Rationale: The correct answer is B: Interference. Interference is the term used to describe the phenomenon when two waves combine to form a new wave. When waves interact constructively or destructively, they interfere with each other, resulting in a new wave pattern. Choice A, Diffraction, refers to the bending of waves around obstacles, not the combination of waves. Choice C, Refraction, is the bending of waves as they pass from one medium to another, not the combination of waves. Choice D, Dispersion, is the separation of light into its different colors, not the combination of waves.

4. What is the process in which RNA polymerase copies DNA into RNA, with DNA unwinding and serving as a template while RNA is assembled?

A. Replication
B. Transcription
C. Translation
D. Duplication

Correct answer: B

Rationale: The correct answer is B: Transcription. Transcription is the process where RNA polymerase reads the DNA template strand and synthesizes RNA, following the base-pairing rules. During transcription, DNA unwinds and serves as a template for the assembly of complementary RNA molecules. Replication (Choice A) is the process of making an identical copy of DNA, not RNA from DNA. Translation (Choice C) is the process of synthesizing proteins from mRNA. Duplication (Choice D) is a general term and does not specifically refer to the process described in the question.

5. Which of the following best describes the function of synergists?

A. They assist primary movers in completing specific movements
B. They stabilize the point of origin and provide extra pull near the insertion
C. They help prevent unwanted movement at a joint
D. All of the above

Correct answer: D

Rationale: Synergists play multiple roles in muscle function. They assist primary movers in completing specific movements by working together with them. Additionally, synergists help stabilize the point of origin and provide extra pull near the insertion, contributing to the efficiency of movement. Furthermore, they also help prevent unwanted movement at a joint by ensuring that the intended motion is executed smoothly. Therefore, all the statements in the answer choices accurately describe the functions of synergists, making 'All of the above' the most comprehensive and precise description of their role.