Particle Model
What is a fluid?
A substance that can flow (liquids and gases)
What is a pure substance?
Matter made of only one type of particle
What is a solute?
The substance that gets dissolved
What is viscosity?
How thick or resistant to flow a fluid is
What is the formula for density?
Density = Mass ÷ Volume
How are fluid particles different from solid particles?
They move more freely and slide past each other
What is a solution?
A homogeneous mixture—looks like one thing
What is a solvent?
The substance that does the dissolving
What flows faster—high viscosity or low viscosity?
Low viscosity flows faster
What are the units for density?
g/mL or g/cm³
Why do fluids take the shape of their container?
Because their particles move around and aren’t fixed
What is a mechanical mixture?
A heterogeneous mixture—you can see different parts
What does "soluble" mean?
Can dissolve in a solvent
How does heating affect a liquid’s viscosity?
It makes the viscosity lower (flows faster)
How can you make something float better?
Decrease density (lower mass or increase volume)
What does it mean to "flow"?
To move and take the shape of a container
Is air a mixture or a pure substance?
A mixture (of gases)
What are two ways to speed up dissolving?
Stirring, heating, crushing
How does heating affect a gas’s viscosity?
It increases viscosity (more collisions)
What is neutral buoyancy?
When an object’s density equals the fluid’s
Why don’t solids flow?
Their particles are tightly packed and don’t move freely
Give an example of a solution and a mechanical mixture.
Salt water & salad
Why is water called the universal solvent?
It dissolves more substances than any other liquid
What’s the difference between viscosity and flow rate?
Viscosity = resistance to flow; Flow rate = how fast it moves
What happens when an object is more dense than the fluid?
It sinks (negative buoyancy)