TEAS 7 Chemistry: Essential Practice for Success

ATI TEAS 7

Chemistry

1. Which of the following is NOT a characteristic of a chemical reaction?

A. Formation of new substances
B. Release or absorption of energy
C. Change in color
D. Change in temperature

Correct answer: C

Rationale: While color change can be an indicator of a chemical reaction, it's not always present, and some reactions occur without a visible color change.

2. The spleen, an organ associated with the lymphatic system, plays a crucial role in:

A. Regulating blood sugar levels
B. Filtering blood and destroying old red blood cells
C. Producing digestive enzymes
D. Secreting hormones

Correct answer: B

Rationale: The correct answer is B: 'Filtering blood and destroying old red blood cells.' The spleen is part of the lymphatic system and acts as a blood filter, removing old or damaged red blood cells and helping to fight infections. It does not play a role in regulating blood sugar levels (A), producing digestive enzymes (C), or secreting hormones (D). Understanding the function of the spleen in filtering blood and removing old red blood cells is crucial for grasping its role in maintaining overall health and immunity.

3. How can the periodic table be used to predict the charge of an ion formed by an element?

A. Look for elements with similar atomic weights.
B. Identify the group number, which corresponds to the typical ionic charge.
C. Calculate the difference between protons and electrons.
D. Analyze the element's position within the period.

Correct answer: B

Rationale: Identify the group number, which corresponds to the typical ionic charge. Elements tend to gain or lose electrons to achieve a stable electron configuration like the noble gas group. Their group number often indicates the number of electrons gained/lost and the resulting ionic charge.

4. Which hormone, produced by the pancreas, is involved in the regulation of blood sugar levels by inhibiting the release of insulin and promoting the release of glucose into the bloodstream?

A. Insulin
B. Glucagon
C. Cortisol
D. Somatostatin

Correct answer: D

Rationale: The correct answer is D: Somatostatin. Somatostatin is a hormone produced by the pancreas that plays a key role in regulating blood sugar levels. It inhibits the secretion of insulin, which helps prevent a further decrease in blood sugar levels. Additionally, somatostatin promotes the release of glucose into the bloodstream by inhibiting the release of other hormones that would lower blood sugar levels. This dual action of somatostatin helps maintain blood sugar within a normal range. While insulin is involved in lowering blood sugar levels by promoting glucose uptake, glucagon stimulates the release of glucose from storage to increase blood sugar levels. Cortisol is a steroid hormone produced by the adrenal glands that plays a role in stress response and metabolism, but it is not directly involved in regulating blood sugar levels.

5. Which statement accurately describes the electron cloud model of the atom?

A. Electrons precisely orbit the nucleus in defined paths.
B. Electrons occupy specific energy levels around the nucleus with varying probabilities.
C. Electrons are clustered tightly within the nucleus.
D. Electrons move randomly throughout the entire atom.

Correct answer: B

Rationale: Electrons occupy specific energy levels around the nucleus with varying probabilities. The electron cloud model depicts electrons existing in distinct energy levels, not fixed orbits, with probabilities of finding them in specific regions.