an element with atomic number 26 and mass number 56 is most likely to be

ATI TEAS 7

ati teas 7 science

1. An element with atomic number 26 and mass number 56 is most likely to be:

A. Iron (Fe)
B. Cobalt (Co)
C. Nickel (Ni)
D. Manganese (Mn)

Correct answer: A

Rationale: The element with atomic number 26 and mass number 56 corresponds to Iron (Fe). Iron has 26 protons, which aligns with the given atomic number, and Fe-56 has 26 neutrons, which aligns with the given mass number. This confirms that Iron (Fe) is the correct answer. Cobalt (Co), Nickel (Ni), and Manganese (Mn) have different atomic numbers and mass numbers, so they are not the correct choices in this scenario.

2. What is the function of valves in arteries?

A. To maintain high blood pressure for the proper diffusion of nutrients in capillaries.
B. To prevent backflow of blood due to high pressure away from the heart.
C. As a vestigial trait from evolution, like the appendix, that serves no purpose.
D. Valves are absent in arteries but present in veins.

Correct answer: B

Rationale: Valves in arteries serve the crucial function of preventing backflow of blood. Arteries carry blood at high pressure away from the heart, and the valves ensure that blood flows in one direction, towards the capillaries, to maintain efficient circulation. Without these valves, there would be a risk of blood flowing backward, compromising the effectiveness of blood circulation in the body. Choices A, C, and D are incorrect. Choice A incorrectly suggests that valves maintain high blood pressure for nutrient diffusion in capillaries, which is not their function. Choice C inaccurately compares valves to vestigial traits, like the appendix, implying they serve no purpose, which is untrue. Choice D is incorrect as valves are indeed present in arteries to regulate blood flow, not just in veins.

3. Which organ plays a significant role in immune cell production and maturation?

A. Liver
B. Kidneys
C. Bone marrow
D. Spleen

Correct answer: C

Rationale: The bone marrow is the correct answer. It is the primary site for immune cell production and maturation. The bone marrow is responsible for generating various types of blood cells, including white blood cells crucial for the immune system's function. The liver, kidneys, and spleen have essential functions in the body, such as filtering blood, detoxification, and storage of blood, respectively. However, they are not primarily involved in immune cell production and maturation, making them incorrect choices for this question.

4. Isotopes are variants of a single element that differ in:

A. Having the same number of protons but varying numbers of neutrons
B. Having the same number of neutrons but varying numbers of protons
C. Having the same mass but different atomic numbers
D. None of the above

Correct answer: A

Rationale: Isotopes are variants of a single element that have the same number of protons, the defining characteristic of an element. They differ in the number of neutrons they possess, leading to isotopes having different atomic masses while retaining the same chemical properties. Choice B is incorrect because isotopes have the same number of neutrons and differ in the number of protons. Choice C is incorrect because isotopes have different masses due to varying numbers of neutrons, not different atomic numbers. Choice D is incorrect as isotopes do differ in the number of neutrons they possess.

5. During ejaculation, sperm travels through a tube from the testes to the urethra. What is the name of this tube?

A. Vas deferens
B. Epididymis
C. Seminal vesicle
D. Urethra

Correct answer: A

Rationale: The vas deferens is the correct answer. It is the tube that carries sperm from the testes to the urethra during ejaculation. The vas deferens plays a crucial role in transporting mature sperm for ejaculation. The epididymis is responsible for sperm maturation and storage, not the direct passage of sperm to the urethra. The seminal vesicle produces fluid that combines with sperm to form semen but is not the tube for sperm transport. The urethra serves as the passageway for both urine and semen out of the body but is not the specific tube that transports sperm from the testes to the urethra.