TEAS 7 Chemistry: Essential Practice for Success

ATI TEAS 7

Chemistry

1. What information can be obtained from the mass number of an element?

A. The number of protons in the nucleus
B. The total number of protons and neutrons
C. The number of electrons in the valence shell
D. The element's chemical reactivity

Correct answer: B

Rationale: The mass number of an element represents the total number of protons and neutrons in the nucleus. This information is crucial for determining the atomic mass of the element and understanding its stability and isotopes. The number of protons in the nucleus (option A) is represented by the atomic number, not the mass number. The number of electrons in the valence shell (option C) is related to the element's position in the periodic table and its chemical properties, but it is not directly determined by the mass number. The element's chemical reactivity (option D) is influenced by the number and arrangement of electrons in the atom's energy levels, not by the mass number.

2. Aromatic compounds

A. Contain a ring structure with alternating single and double bonds
B. Readily undergo addition reactions
C. Are easily broken down by water
D. Do not contain any pi (Ãâ‚¬) bonds

Correct answer: A

Rationale: The correct answer is A: 'Aromatic compounds contain a ring structure with alternating single and double bonds.' Aromatic compounds exhibit a special stability due to the delocalization of pi electrons within the ring, known as resonance. This resonance occurs because of the alternating single and double bonds in the ring structure, making them less reactive towards addition reactions compared to alkenes, which have only double bonds. This stability also makes aromatic compounds less likely to be easily broken down by water, as they are relatively inert in many chemical reactions. Therefore, aromatic compounds do contain pi (Ï€) bonds due to the presence of the alternating single and double bonds in their ring structure.

3. What property of matter refers to the amount of space occupied by an object and is measured in cubic units?

A. Mass
B. Density
C. Weight
D. Volume

Correct answer: d

Rationale: Volume is the property that refers to the amount of space occupied by an object and is measured in cubic units such as cubic meters or cubic centimeters.

4. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

A. Schwann cells
B. Astrocytes
C. Neurons
D. Oligodendrocytes

Correct answer: A

Rationale: The correct answer is A: Schwann cells. Schwann cells are a type of glial cell in the peripheral nervous system that produce the myelin sheath around axons. Myelin sheath is essential for the rapid conduction of nerve impulses and provides insulation and protection to nerve fibers. Astrocytes are glial cells that provide support and maintain homeostasis in the central nervous system, but they do not produce myelin. Neurons are the main functional units of the nervous system responsible for transmitting nerve impulses. Oligodendrocytes are another type of glial cell in the central nervous system that produce myelin sheath around axons in that region, not in the peripheral nervous system where Schwann cells are responsible for myelination.

5. Which of the following nutrients is essential for muscle growth and repair?

A. Vitamin C
B. Protein
C. Carbohydrates
D. Fat

Correct answer: B

Rationale: The correct answer is B: Protein. Protein is essential for muscle growth and repair because it provides the necessary building blocks called amino acids. These amino acids are crucial for repairing and building muscle tissue, which is essential for overall muscle growth and recovery. While vitamins like Vitamin C play a role in overall health and immune function, they are not directly involved in muscle growth and repair. Carbohydrates provide energy for workouts, but they are not the primary nutrient needed for muscle repair. Fat is important for overall health but is not as directly involved in muscle growth and repair as protein is.