group iia elements have what charge

HESI A2

Chemistry HESI A2 Quizlet

1. What charge do Group IIA elements typically have?

A. 1
B. +2
C. -3
D. 0

Correct answer: B

Rationale: Group IIA elements belong to the alkaline earth metals group in the periodic table. These elements typically have a charge of +2 because they readily lose two electrons to achieve a stable electron configuration. Therefore, the correct answer is B - +2. Choice A (1) is incorrect because Group IIA elements lose two electrons, not one. Choice C (-3) is incorrect because Group IIA elements do not gain electrons to have a negative charge. Choice D (0) is incorrect because Group IIA elements do lose electrons and have a positive charge, not a neutral charge.

2. Where do nearly all of the gaseous exchanges between air and blood take place in the lungs?

A. Pleura
B. Trachea
C. Bronchioles
D. Alveoli

Correct answer: D

Rationale: Nearly all gaseous exchanges between air and blood take place in the alveoli of the lungs. The walls of the alveoli are thin and surrounded by an extensive network of tiny blood vessels called capillaries. Oxygen from the air diffuses through the alveoli walls and into the bloodstream, while carbon dioxide, a waste product, diffuses from the blood into the alveoli to be exhaled out of the body. This process is essential for respiration and providing oxygen to the body's cells. Choices A, B, and C are incorrect. Pleura is the membrane surrounding the lungs, trachea is the windpipe that carries air to the lungs, and bronchioles are the smaller air passages in the lungs. However, the primary site for gaseous exchange is the alveoli due to their structure and function.

3. Subtract 17 2\3 - 8 5\9.

A. 8 4\9
B. 9 1\9
C. 8 3\9
D. 8 4\9

Correct answer: B

Rationale: Find a common denominator to subtract: 17 2\3 - 8 5\9 = 9 1\9.

4. If a rat can finish a maze in about 3 minutes, how much longer will it take the rat to finish the maze if a small backpack is put on it, reducing its speed by 50%?

A. 3 minutes
B. 4 minutes
C. 6 minutes
D. 1.5 minutes

Correct answer: C

Rationale: Reducing the rat's speed by 50% means it will take twice as long to finish the maze. Since the original time is 3 minutes, doubling that gives 6 minutes. Therefore, the total time will be 6 minutes, making the correct answer C. Choice A (3 minutes) is the original time it takes the rat to finish the maze, not the time with the backpack. Choice B (4 minutes) is not correct as reducing the speed by 50% would double the original time. Choice D (1.5 minutes) is incorrect as halving the time is not the effect of reducing the speed by 50%.

5. What is the meaning of the word moderation as used in the second paragraph?

A. Adequate amounts
B. Intervals of time
C. Excess
D. Variation

Correct answer: A

Rationale: In this context, moderation means consuming adequate amounts of unsaturated fats. The passage highlights that unsaturated fats like olive oil and omega-3 fatty acids are beneficial when consumed in appropriate quantities. Choice B, intervals of time, is incorrect as it does not relate to the consumption of fats. Choice C, excess, is incorrect because moderation implies avoiding excess consumption. Choice D, variation, is unrelated to the context of consuming fats in appropriate amounts.