1. A new drug successfully treats a disease in mice. This suggests the drug will also be effective in humans. True or False? False. Animal models don't always perfectly translate to humans due to biological differences. Further testing in humans is crucial before drawing conclusions about safety and efficacy. A conclusion based on scientific evidence should be:

A. Unquestionable and accepted by all scientists.
B. Open to revision and further testing as new evidence emerges.
C. Based solely on expert opinions and authority figures.
D. Always presented as absolute truth with no room for doubt.

Correct answer: B

Rationale: Scientific conclusions should always be open to revision and further testing as new evidence emerges. Science is a dynamic process that involves continuous questioning, testing, and refining of ideas based on the most current evidence available. It is essential to remain open-minded and willing to adjust conclusions in light of new information to ensure the most accurate and reliable understanding of the natural world.

2. Which force opposes the relative motion between surfaces in contact?

A. Tension force
B. Frictional force
C. Gravitational force
D. Magnetic force

Correct answer: b

Rationale: Friction is the force that opposes motion between surfaces in contact.

3. The sentence "The audience was captivated by the speaker's compelling story" implies that the audience:

A. Was bored and disinterested.
B. Found the story confusing.
C. Was completely absorbed and engaged.
D. Disagreed with the speaker's message.

Correct answer: C

Rationale: "Captivated" suggests the audience was completely held by the speaker's story.

4. An object is moving in a circle at constant speed. Is there a net force acting on it?

A. Yes, always
B. No, never
C. Only if its speed is changing
D. Only if its direction is changing

Correct answer: A

Rationale: Even though the speed is constant, the direction is constantly changing, requiring a centripetal force to keep the object moving in a circle.

5. 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.

6. Which of the following numbers is a perfect square?

A. 10
B. 12
C. 15
D. 16

Correct answer: D

Rationale: A perfect square is a number obtained by squaring an integer. 16 is the result of squaring 4 (4 x 4 = 16). The other answer choices are not the product of squaring any whole number.