Science TEAS Practice Test

Correct Answer: B

Rationale: The correct answer is B: A model. A model is a representation of a natural pattern or occurrence that simplifies complex systems to make them easier to understand and study. Models can simulate natural phenomena that are difficult or impossible to experience directly, allowing scientists to make predictions and test hypotheses. The other choices are incorrect because: A: A theory is an explanation based on evidence and reasoning, not necessarily something difficult to experience directly. C: A law describes a recurring phenomenon but may not involve a representation or simulation of the phenomenon. D: An observation is a direct act of seeing or noting something, not a representation of a complex natural pattern.

Correct Answer: D

Rationale: Density is considered an intensive property because it remains constant regardless of the amount of the substance present. Intensive properties do not depend on the quantity of the material. Density is defined as mass per unit volume, so it is independent of the amount of the substance. On the other hand, mass and volume (choices A and C) are extensive properties that change with the amount of the substance, making them not intensive. Weight (choice B) is also not an intensive property as it depends on the gravitational force acting on the object, which can vary.

Correct Answer: B

Rationale: The correct answer is B, "Most of them are gases at room temperature." Metals are typically solid at room temperature, not gases. This is because metals have high melting points due to their metallic bonding structure. Choice A is true as most metals are good conductors of heat due to the free movement of electrons. Choice C is also true, as metals are ductile and can be drawn into wires. Choice D is incorrect, as metals do not make up the majority of elements on the periodic table. Nonmetals, metalloids, and noble gases also exist.

Correct Answer: D

Rationale: The correct answer is D: Plasma cells. Plasma cells are a type of white blood cell that produces and secretes antibodies, which are essential for the immune response. Plasma cells are specifically designed to produce antibodies to fight off infections. Bacterial cells (choice A) and viral cells (choice B) do not secrete antibodies as they are pathogens. Lymph cells (choice C) are a general term for various types of white blood cells, including plasma cells, but not all lymph cells secrete antibodies. Plasma cells, on the other hand, are specialized for antibody production, making choice D the correct answer.

Correct Answer: D

Rationale: The correct answer is D: Ionic bond. In an ionic bond, electrons are transferred from one atom to another, resulting in the formation of positively and negatively charged ions that are attracted to each other. This transfer of electrons leads to the creation of a strong bond between the atoms. A: Transfer bond is not a recognized term in chemistry. B: Static bond is not a valid type of bond in chemistry. C: Covalent bond involves the sharing of electrons between atoms, not the transfer of electrons like in an ionic bond.