Simple Particle Model
What is the particle model?
This model explains matter as made of small, moving particles.
What are the three main states of matter?
Solid, liquid, and gas.
What is the process of turning liquid into a gas?
Evaporation
How does one calculate density?
Density = Mass / Volume
The unit commonly used for density is...
g/cm3 or kg/m3
What would the state be when particles are tightly packed in a fixed pattern?
What is a solid?
This state has tightly packed particles.
Adding heat to ice causes what change in state?
Solid to liquid - melting.
Two substances have the same volume but one has more mass. Is the one with more mass denser?
Yes, the one with more mass has a higher density.
How do you find the volume of an irregular object?
Water displacement method.
What is a liquid?
This state has particles that flow and slide past each other but stay close together.
What state takes the shape and volume of its container?
Condensation is what?
Removing heat from a gas causes it to become a liquid.
According to the particle model, a dense object has particles that are...
Tightly packed together.
What is a balance or scale used for?
To measure mass in density experiments.
What is freely moving and quick in all directions?
Gas particles behave like this in the particle model.
What state can flow but has a definite volume?
What is deposition?
The term for a gas changing directly to a solid.
When a gas is heated up the density will...
decrease because particles become more spead out.
In an experiment, an object has a mass of 60g and a volume of 20cm³. What is its density?
60g/20cm3 = 3 g/cm3
What is one benefit and one limitation of the particle model?
Benefit: easy to understand changes in states
Limitation: doesn't show forces between particles well.
Why can gases be compressed easily, but solids and liquids cannot?
Gas particles are far apart and have lots of empty space between them, hence they can be pushed closer together. In solids and liquids particles are already close together with little space, so cannot be compressed easily.
Explain why a cold can of drink "sweats" on a hot day using particle theory.
Warm air loses energy near the cold can, causing gas particles to slow down and condense into liquid.
Why does ice float in water based on density?
Ice floats in water because it is less dense than liquid water.
When water freezes, its particles arrange in a way that takes up more space. This means there are fewer particles in a given volume, making ice less dense than the same volume of liquid water - so it floats.
You place a rock in a measuring cylinder filled with water. The water level rises from 60 mL to 85 mL. If the rock’s mass is 50 g, what is its density?
V = 85mL - 60mL = 25cm3
D = 50 / 25 = 2g/cm3