which of the following properties is not characteristic of a covalent bond

ATI TEAS 7

TEAS 7 practice test science

1. Which of the following properties is NOT characteristic of a covalent bond?

A. Sharing of electrons between atoms
B. High melting and boiling points
C. Low electrical conductivity in solid state
D. Directional bonding

Correct answer: B

Rationale: Covalent bonds are formed by the sharing of electrons between atoms, leading to the formation of molecules with directional bonding. This means that the atoms are held together in a specific orientation. Covalent compounds generally exhibit low melting and boiling points compared to ionic compounds due to the weaker intermolecular forces present in covalent compounds. Furthermore, covalent compounds do not conduct electricity in the solid state because the electrons are localized between the atoms and are not free to move and carry charge. Hence, high melting and boiling points are not characteristic of covalent bonds. The correct answer is 'B' because high melting and boiling points are typically associated with ionic compounds due to their strong electrostatic interactions, while covalent compounds have lower melting and boiling points. Choices A, C, and D are all characteristics of covalent bonds, making them incorrect answers for this question.

2. Cartilage is a flexible connective tissue found in the:

A. Center of long bones
B. Joints between bones
C. Muscle tissue
D. Walls of blood vessels

Correct answer: B

Rationale: Cartilage is a flexible connective tissue found in the joints between bones. It provides cushioning and support for the bones, allowing smooth movement and reducing friction between them. Cartilage acts as a shock absorber and helps maintain the structural integrity of the joints. Choices A, C, and D are incorrect because cartilage is not typically found in the center of long bones, muscle tissue, or the walls of blood vessels. Cartilage primarily functions in providing structural support and flexibility in joints.

3. How is homeostasis defined?

A. The ability of human beings to keep body weight within normal limits.
B. The maintenance of a constant external temperature inside a room.
C. The ingestion of enough food to prevent hunger pains.
D. The tendency of the body to maintain a stable internal environment.

Correct answer: D

Rationale: Homeostasis is defined as the tendency of the body to maintain a stable internal environment despite external changes. This process involves regulating various physiological parameters such as body temperature, blood pressure, and glucose levels to ensure optimal functioning and health. Option A is incorrect as it specifically refers to body weight regulation, which is not the sole focus of homeostasis. Option B is incorrect as it describes maintaining a constant temperature in a room, rather than the internal environment of the body. Option C is incorrect as it only addresses the prevention of hunger pains through food ingestion, which is not the overarching concept of homeostasis.

4. Which of the following is NOT a typical component of healthy semen?

A. Sperm
B. Fructose (sugar)
C. Prostaglandins
D. Urine

Correct answer: D

Rationale: Healthy semen is composed of sperm, fructose (sugar), and prostaglandins. Urine is not a typical component of semen. While semen is ejaculated during sexual activity, urine is expelled through a separate pathway in the male reproductive system. Therefore, the correct answer is 'Urine.' Choices A, B, and C are all components found in healthy semen.

5. Which of the following reagents can be used to convert a primary alcohol to an alkyl halide?

A. HI
B. H2O
C. NaOH
D. SOCl2

Correct answer: D

Rationale: SOCl2 (thionyl chloride) is commonly used to convert primary alcohols to alkyl halides through an SN2 mechanism. Thionyl chloride reacts with the alcohol to form an alkyl chloride. HI (hydroiodic acid) is typically used to convert alcohols to alkyl iodides specifically, not alkyl halides in general. H2O (water) and NaOH (sodium hydroxide) are not reagents used for converting alcohols to alkyl halides. Therefore, the correct answer is SOCl2 as it facilitates the conversion of primary alcohols to alkyl halides, unlike the other options provided.