Particle Model of Matter Flashcards
(74 cards)
What is density defined as?
The mass per unit volume of a material
How do objects made from low density materials compare in mass to those made from high density materials?
Objects made from low density materials typically have a low mass, while similarly sized objects made from high density materials have a high mass
What is the relationship between density, mass, and volume?
Density is related to mass and volume by the equation: density = mass/volume
What are the units of density if mass is measured in grams and volume in cubic centimeters?
g/cm3
What are the units of density if mass is measured in kilograms and volume in cubic meters?
kg/m3
What happens to an object that is more dense than water?
It will sink
How do gases compare in density to solids?
Gases are less dense than solids because the molecules are more spread out
What is the particle model?
A model that describes the arrangement and movement of particles in a substance
What are the three states of matter?
Solid, liquid, gas
Describe the arrangement of particles in a solid.
The particles are closely packed and vibrate about fixed positions
Describe the arrangement of particles in a liquid.
The particles are closely packed but can flow over one another
Describe the arrangement of particles in a gas.
The particles are far apart and move randomly
How does the density of solids and liquids compare?
The density of solids and liquids are roughly the same because their molecules are tightly packed
What is the independent variable in measuring the density of irregularly shaped objects?
Different irregular shapes / mass
In changes of state, what happens to the number of molecules in a substance?
The number of molecules does not change
What is melting?
A solid turns into a liquid when energy is transferred to the system
What is boiling?
A liquid turns into a gas when energy is transferred to the system
What is condensing?
A gas turns into a liquid when energy is transferred away from the system
What is freezing?
A liquid turns into a solid when energy is transferred away from the system
What is subliming?
A solid turns into a gas when energy is transferred to the system
True or False: The mass of a substance changes when it undergoes a physical change.
False
What should you do to minimize random errors in density measurements?
Take repeat readings and calculate an average
What is a common misconception about changes of state?
That the molecules themselves melt and separate
What is internal energy?
The total energy stored inside a system by the particles that make up the system due to their motion and positions.