Unit 7 Review Flashcards
states of matter & properties of fluids
Provide the term: An explanation of how the particles in gases behave.
kinetic theory
The kinetic theory is also known as the kinetic molecular theory.
What are the four assumptions of the kinetic theory?
PRCE
- All matter is composed of tiny particles1
- These particles are in constant, random motion
- The particles collide with each other and with the walls of any container in which they are held.
- The amount of energy that the particles lose from these collisions is negligible.
PARTICLES, RANDOM, COLLIDE, ENERGY
1 Atoms, molecules, and ions
What is a solid?
the state of matter that has a definite shape and volume
the particles in this state do not move fast enough to overcome the attraction between eachother
solid
the particles in this state move quickly and can break away completely from one another
gas
True or false: In a solid, each particle vibrates in place and is locked in place by the particles around it.
True
What are the two types of solids?
- Crystalline
- Amorphous
What type of solid is this?
Crystalline
Crystalline solids have a very orderly, three-dimensional arrangement of particles.
What are some examples of crystalline solids?
- iron
- diamond
- ice
What type of solid is this?
amorphous
Amorphous solids are made of particles that do not have a special arrangement.
What are some examples of amorphous solids?
- glass
- rubber
- wax
What is gas?
the state of matter that has no definite shape or volume
True or false: The amount of empty space between gas particles cannot change.
False
What is liquid?
the state of matter that has a definite volume but takes the shape of its container
the particles of this state move fast enough to overcome some of the attraction between them
liquid
the particles in this state slide past each other
liquid
When you put ice in your drink, why does it eventually melt?
the particles that make up the water are moving fast and colliding with the particles that make up the ice cube
This transfers energy from the water to the ice. The particles at the surface of the ice cube vibrate faster, transferring energy to other particles in the ice cube. Eventually, the ice particles move fast enough to become liquid.
A change of state is the change of a substance from one _______ form to another.
physical
Arrange the three states of matter based on how fast they move.
(1 being the slowest, 3 being the fastest)
- Solids - vibrate
- Liquids - flow
- Gases - bounce
What is melting?
the change of state from a solid to a liquid
What is the melting point1 for water?
anything above 0˚ Celsius
1 The temperature at which a solid changes to a liquid.
Provide the term: The energy required to change a substance from a solid to a liquid.
Heat of fusion (Hfus)
The heat of fusion is the amount of energy required to change a substance from a solid to a liquid at its melting point. It represents the energy needed to overcome intermolecular forces without changing the temperature. In short, the melting point is a temperature, while the heat of fusion is an amount of energy required for the phase change.
For a solid to melt, particles must overcome their __________ to each other.
attraction
What is the difference between an endothermic change and an exothermic one?
- Endothermic - adding (absorbing) energy
- Exothermic - removing (releasing) energy