which of the following is the smallest part of an element that can still be recognized as that element

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. Which of the following is the smallest part of an element that can still be recognized as that element?

A. Electron
B. Proton
C. Neutron
D. Atom

Correct answer: D

Rationale: An atom is the smallest unit of matter that retains the chemical properties of an element. It consists of a nucleus containing protons and neutrons, surrounded by electrons that orbit the nucleus. The number of protons in the nucleus defines the atomic number of the element, and the number of neutrons determines the isotope of the element. While electrons, protons, and neutrons are fundamental particles, an atom as a whole is the smallest part of an element that maintains its unique identity. Electrons are negatively charged particles orbiting the nucleus, protons are positively charged particles in the nucleus, and neutrons are neutral particles in the nucleus. Therefore, the correct answer is 'D: Atom.'

2. In the human skeleton, which of the following lists some of the vertebrae in descending order?

A. Atlas, axis, thoracic, lumbar, sacral, coccyx.
B. Axis, sacral, coccyx, atlas, lumbar, thoracic.
C. Thoracic, sacral, lumbar, axis, coccyx, atlas.
D. Coccyx, lumbar, axis, sacral, thoracic, atlas.

Correct answer: A

Rationale: The correct order of some of the vertebrae in the human skeleton in descending order is Atlas, Axis, Thoracic, Lumbar, Sacral, Coccyx. This sequence follows the typical arrangement from the top of the spine down towards the pelvis. Choice B is incorrect as it does not follow the descending order of vertebrae. Choice C is incorrect as it starts with Thoracic which is not the first vertebra in the descending order. Choice D is incorrect as it starts with Coccyx which is the last vertebra in the descending order.

3. What are the four chambers of the heart?

A. Right atrium, left atrium, right ventricle, left ventricle
B. Right atrium, left atrium, right ventricle, left atrium
C. Left atrium, right ventricle, left ventricle, right atrium
D. Left atrium, right atrium, left ventricle, right ventricle

Correct answer: A

Rationale: The correct answer is A: Right atrium, left atrium, right ventricle, left ventricle. The heart consists of four chambers: the right atrium, left atrium, right ventricle, and left ventricle. Blood flows from the body into the right atrium, then to the right ventricle, where it is pumped to the lungs for oxygenation. Oxygenated blood returns to the left atrium, passes to the left ventricle, and is then pumped out to the body. Choice B is incorrect because it incorrectly lists the left atrium twice. Choice C is incorrect as it rearranges the order of the chambers. Choice D is incorrect as it mistakenly switches the atria and ventricles in their positions.

4. Which of the following distinguishes the isotopes of an element?

A. Isotopes are atoms of the same element that have different ionic charges.
B. Isotopes are atoms of elements within the same group on the periodic table.
C. Isotopes are atoms of the same element that have different numbers of neutrons.
D. Isotopes are atoms of the same element with different electron configurations.

Correct answer: C

Rationale: Isotopes are defined as atoms of the same element that have the same number of protons in their nucleus but different numbers of neutrons. This leads to variations in atomic mass for isotopes of an element. The different number of neutrons in isotopes results in differences in their atomic mass and properties while still belonging to the same element. Choice A is incorrect because isotopes do not have different ionic charges, they have the same chemical properties. Choice B is incorrect because isotopes are not atoms of elements within the same group on the periodic table; they are variants of the same element. Choice D is incorrect because isotopes of an element have the same electron configuration, differing only in the number of neutrons in the nucleus.

5. Identify the correct sequence of the 3 primary body planes as numbered 1, 2, and 3 in the above image.

A. Plane 1 is coronal, plane 2 is sagittal, and plane 3 is transverse.
B. Plane 1 is sagittal, plane 2 is coronal, and plane 3 is medial.
C. Plane 1 is coronal, plane 2 is sagittal, and plane 3 is medial.
D. Plane 1 is sagittal, plane 2 is coronal, and plane 3 is transverse.

Correct answer: A

Rationale: In the standard anatomical position, plane 1 (coronal/frontal plane) divides the body into anterior and posterior portions, plane 2 (sagittal plane) divides the body into left and right portions, and plane 3 (transverse/horizontal plane) divides the body into superior and inferior portions. Therefore, the correct sequence is Plane 1 as coronal, Plane 2 as sagittal, and Plane 3 as transverse, which corresponds to Choice A. Choice B is incorrect as it misidentifies the planes. Plane 2 cannot be coronal as it specifically divides the body into left and right portions. Choice C is incorrect as it misidentifies Plane 2 as sagittal when it should be coronal. Choice D is incorrect as it incorrectly designates Plane 2 as coronal when it should be sagittal, leading to an inaccurate sequence of the primary body planes.