Science Flashcards
(61 cards)
What are the main points of the particle model of matter?
All matter is made of tiny particles, they have space between them, they’re always moving, and they attract each other.
What is the difference between a pure substance and a mixture?
A pure substance has only one type of particle; a mixture has two or more types.
What is viscosity and how does temperature affect it?
Viscosity is how thick a fluid is. Higher temperatures usually lower viscosity.
What is viscosity and how does temperature affect it?
Viscosity is how thick a fluid is. Higher temperatures usually lower viscosity.
What is buoyancy?
The upward force a fluid applies to an object; objects float if buoyant force is greater than their weight.
What are the 7 characteristics of living things?
Made of cells, grow, reproduce, respond to environment, use energy, produce waste, need nutrients.
What are the main parts of a plant cell?
Cell wall, cell membrane, nucleus, chloroplasts, cytoplasm, vacuole.
What is diffusion?
Movement of particles from high to low concentration.
What is osmosis?
Movement of water through a membrane from high to low concentration.
What is the difference between luminous and non-luminous objects?
Luminous objects produce light; non-luminous objects reflect light.
What is reflection?
When light bounces off a surface.
What is refraction?
Bending of light as it passes from one material to another.
How does a concave lens affect light?
It spreads light rays out (diverges).
What are the main parts of the eye?
Cornea, lens, retina, pupil, iris, optic nerve.
What is a simple machine?
A tool that makes work easier (e.g., lever, pulley, inclined plane).
What is a gear?
A rotating wheel with teeth that transfers motion and force.
What is a simple machine?
A tool that makes work easier (e.g., lever, pulley, inclined plane).
What is a gear?
A rotating wheel with teeth that transfers motion and force.
What’s the difference between speed and force advantage?
Speed advantage = faster motion, less force; force advantage = more force, less speed.
What is the water cycle?
The movement of water through evaporation, condensation, precipitation, and runoff.
What are the main types of water on Earth?
Saltwater (oceans) and freshwater (lakes, rivers, groundwater, glaciers).
How are glaciers formed?
From layers of snow that compress into ice over time.
What affects aquatic ecosystems?
Temperature, light, nutrients, pollution, and oxygen levels.
What percentage of Earth’s water is fresh water?
About 3%.
