TEAS 7 Chemistry: Essential Practice for Success

ATI TEAS 7

Chemistry

1. In a single displacement reaction, one element takes the place of another element in a compound. Which of the following is an example?

A. 2H2 + O2 -> 2H2O
B. Zn + 2HCl -> ZnCl2 + H2
C. CaCO3 -> CaO + CO2
D. CH4 + 2O2 -> CO2 + 2H2O

Correct answer: B

Rationale: In a single displacement reaction, one element replaces another element in a compound. Option B, 'Zn + 2HCl -> ZnCl2 + H2,' is an example of a single displacement reaction where zinc (Zn) replaces hydrogen (H) in hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2). The other options do not involve one element displacing another in a compound. Option A is a synthesis reaction, option C is a decomposition reaction, and option D is a combustion reaction. Therefore, option B is the correct answer as it demonstrates the concept of single displacement reactions.

2. A routine urinalysis is a common diagnostic test. What does a urinalysis typically evaluate?

A. Blood sugar levels
B. Presence of white blood cells (indicating possible infection)
C. Kidney function
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' A routine urinalysis is a comprehensive test that evaluates various aspects of urine to provide insights into overall health. Blood sugar levels can be assessed to screen for diabetes or monitor diabetes management. The presence of white blood cells in the urine can indicate a possible infection in the urinary tract. Additionally, kidney function can be evaluated by examining factors such as protein levels, creatinine, and electrolytes in the urine. Therefore, a urinalysis typically evaluates blood sugar levels, presence of white blood cells (indicating possible infection), and kidney function, making 'All of the above' the correct choice.

3. 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. This sharing results in the formation of molecules with directional bonding, where the atoms are held together in a specific orientation. Covalent compounds generally have low melting and boiling points compared to ionic compounds, as the intermolecular forces in covalent compounds are weaker. Additionally, covalent compounds do not conduct electricity in the solid state because the electrons are localized between the atoms and not free to move and carry charge.

4. The hormone responsible for the "fight-or-flight" response in stressful situations is produced by the:

A. Thyroid gland
B. Pituitary gland
C. Adrenal gland
D. Pancreas

Correct answer: C

Rationale: The correct answer is C: Adrenal gland. The adrenal gland is responsible for producing the hormone known as adrenaline, which triggers the 'fight-or-flight' response in stressful situations. This response prepares the body to either confront the stressor or flee from it. The thyroid gland (A) is responsible for producing hormones that regulate metabolism, growth, and development. The pituitary gland (B) controls several other endocrine glands and produces a variety of hormones. The pancreas (D) is responsible for producing insulin and glucagon, which regulate blood sugar levels but are not directly involved in the 'fight-or-flight' response.

5. Which of the following is the main organ responsible for regulating sleep?

A. Thalamus
B. Hypothalamus
C. Pituitary gland
D. Pineal gland

Correct answer: B

Rationale: Rationale: The hypothalamus is the main organ responsible for regulating sleep. It plays a crucial role in controlling the body's circadian rhythm, which is the internal clock that regulates the sleep-wake cycle. The hypothalamus receives input from the eyes about light and darkness, which helps in determining when it is time to sleep or wake up. It also regulates the production of melatonin by the pineal gland, which is a hormone that helps control sleep patterns. While the thalamus is involved in relaying sensory information to the brain, the pituitary gland is responsible for producing and releasing hormones, and the pineal gland produces melatonin under the control of the hypothalamus.