which of the following describes how atomic radius varies across the periodic table

ATI TEAS 7

TEAS 7 Science Practice Test

1. 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.

2. What is the function of a cell wall?

A. To provide structural support for the cell
B. To transport substances in and out of the cell
C. To synthesize proteins and lipids
D. To store genetic material

Correct answer: A

Rationale: The cell wall is a rigid layer that surrounds the cell membrane in plant cells, fungi, and some bacteria. Its main function is to provide structural support and protection for the cell, helping maintain the cell's shape and preventing it from bursting or collapsing. The cell wall also allows for the passage of water, ions, and other molecules in and out of the cell. Options B, C, and D are incorrect because those functions are typically carried out by other cellular structures. Option B is performed by the cell membrane, option C by ribosomes, and option D by the nucleus, which stores genetic material.

3. Which hormone, produced by the adrenal glands, helps regulate the body's response to stress, including increasing blood pressure and suppressing the immune system?

A. Aldosterone
B. Epinephrine
C. Cortisol
D. Insulin

Correct answer: C

Rationale: Cortisol is the correct answer. It is the hormone produced by the adrenal glands that helps regulate the body's response to stress. Cortisol plays a crucial role in increasing blood pressure and suppressing the immune system during stressful situations. Aldosterone, another hormone from the adrenal glands, primarily regulates salt and water balance in the body, not the stress response. Epinephrine, also known as adrenaline, is produced by the adrenal glands in response to stress, but its effects are more immediate and short-lived compared to cortisol. Insulin, produced by the pancreas, regulates blood sugar levels and is not directly involved in the body's response to stress.

4. What is the scientific term for scar tissue?

A. Epithelial tissue
B. Fibrous connective tissue
C. Cartilage
D. Adipose tissue

Correct answer: B

Rationale: The correct scientific term for scar tissue is fibrous connective tissue. Scar tissue is primarily composed of fibrous connective tissue, which forms as part of the body's natural healing process in response to injury or trauma. Epithelial tissue, cartilage, and adipose tissue are not typically involved in scar formation. Therefore, the correct answer is fibrous connective tissue, as it is the specific type of tissue that makes up scar tissue.

5. In a study where fish are fed different amounts of food daily for four weeks in separate tanks, with fish weight measured weekly, what is the dependent variable?

A. Weight of the fish
B. Type of food used
C. Number of fish tanks
D. Frequency of feedings

Correct answer: A

Rationale: The weight of the fish is the dependent variable in this study because it is the outcome being measured in response to the varying feeding amounts. The weight of the fish changes based on the feeding regimen, making it the dependent variable. The type of food used (choice B), number of fish tanks (choice C), and frequency of feedings (choice D) are not the dependent variables in this study. These factors may be independent variables that are manipulated or controlled in the experiment to observe their impact on the dependent variable, which is the weight of the fish.