General Fundamental Scientific Principles 5 — Questions and Answers
Question 1: What is the term for the minimum energy required to start a chemical reaction?
- Enthalpy
- Activation energy (Correct answer)
- Gibbs free energy
- Bond dissociation energy
Correct answer: Activation energy
Activation energy is the minimum energy reactant molecules must have for a reaction to occur, often depicted as a hill on an energy diagram.
Question 2: What phenomenon explains why a straw appears bent when placed in a glass of water?
- Reflection
- Diffraction
- Refraction (Correct answer)
- Dispersion
Correct answer: Refraction
Refraction is the bending of light as it passes from one medium to another with a different optical density, changing its speed.
Question 3: Which subatomic particle has no electric charge?
- Proton
- Electron
- Neutron (Correct answer)
- Positron
Correct answer: Neutron
Neutrons are neutral particles found in the atomic nucleus alongside protons, contributing to atomic mass but not charge.
Question 4: What is the name of the process by which water moves through a semipermeable membrane from low to high solute concentration?
- Diffusion
- Active transport
- Osmosis (Correct answer)
- Facilitated diffusion
Correct answer: Osmosis
Osmosis is the passive movement of water across a semipermeable membrane toward the region of higher solute concentration.
Question 5: According to Einstein's mass-energy equivalence, what does E = mc² tell us?
- Energy and momentum are interchangeable
- Mass can be converted to energy and vice versa (Correct answer)
- The speed of light depends on mass
- Energy increases linearly with velocity
Correct answer: Mass can be converted to energy and vice versa
E = mc² shows that mass and energy are two forms of the same thing, with the speed of light squared as the conversion factor.
Question 6: What is the term for a reaction that absorbs energy from its surroundings?
- Exothermic
- Exergonic
- Endothermic (Correct answer)
- Catalytic
Correct answer: Endothermic
Endothermic reactions absorb heat from the surroundings, causing the environment to feel cooler, as seen with cold packs.
Question 7: Which of Newton's laws explains why a rocket accelerates when exhaust gases are expelled backward?
- First Law (Law of Inertia)
- Second Law (F = ma)
- Third Law (Action-Reaction) (Correct answer)
- Law of Universal Gravitation
Correct answer: Third Law (Action-Reaction)
Newton's Third Law states every action has an equal and opposite reaction — expelled gases push the rocket forward.
General Fundamental Scientific Principles 5
What is the term for the minimum energy required to start a chemical reaction?