Chapter 2: Solids, Liquids, and Gases
Fluid
"Substance that flows", is when then particles move freely and allow the substance to flow from place to place.
Surface tension
-Is the force that holds atoms in a liquid together. -Is the result of an inward pull among the molecules of a liquid that brings the molecules on the surface together; cause the surface to act as if it has a thin skin.
Amorphous solids
-The particles are not arranged in a regular pattern -have no geometric pattern. -dont melt at a distinct temperature
Particles of a solid
-The particles are packed very closely together -Are locked in position and can only vibrate in place
Pressure
-the force pushing on a surface divided by the area of the surface -it is a factor that you can feel it.
1 KPa
= 1,000 Pascal
Charles' law
A principle that describes the relationship between the temperature and volume of a gas at constant pressure. -directly proportional
directly proportional
A term used to describe the relationship between two variables whose graph is a straigh line passing throught the point (0,0).
Third law
At a constant volume, the pressure and the temperature are directly proportional
Vaporization
Change in state from a liquid to gas. -it occurs when the particles in a liquid gain enough energy to move independently.
Sublimation
Change in state from solid to gas without passing through the liquid state.
formula of pressure
Force ------ Area
Jacques Charles
French scientist, examined the relationship between the temperature and volume of a gas that is kept at a constant pressure. He measured the volume of a gas at various temperatures in a container that could change volume.
Liquid
Has a definite volume and acquire the shape of its container (no shape of its own).
Gas
Has neither definite shape nor a definite volume.
Temperature
Is a measure of the average energy of motion of the particles of a substance. -how hot or cold something is.
Viscosity
Is the resistance of liquid to flow.
Freezing point
Is when the particles of a substance are moving so slowly that they begin to take on fixed positions.
Particles of a liquid
Move around one another freely.
Crystalline solids
The particles form a regular, repeating pattern that creases crystals, geometric pattern.
The difference between amorphous and crystalline solids
The pattern of how they are made and the melting point.
Evaporation
The process by which molecules at the surface of a liquid absorb enough energy to change to a gas.
Boiling point
The temperature at which a liquid boils.
Particles of a gas
They spread apart, filling all the space available.
Boiling
Vaporization that occurs at and below the surface of a liquid.
Example of a solid
a pencil
Boyle's law
a principle that describes the relationship between the pressure and volume of a gas at constant temperature. -inversely proportional
Example of evaporation:
a shrinking puddle, water in the puddle gains energy from the ground, the air or the sun, and the added energy enables some of the water molecules on the surface of the puddle to escape into the air (evaporate).
inversely proportional
a term used to describe the relationshipe between two variables whose product is constant.
atm
atmósfera
You can observe condensation by...
breathing into a mirror
Deposition
change of matter from gas to solid
Volume is measured in:
cm^3, m^3, mL, and L
Solid
definite shape and a definite volume.
example of sublimation
dry ice (solid carbon dioxide) carbon dioxide cannot exist as a liquid so instead of melting, it changes directly to gas, as it sublimes it absorbs thermal energy, this property helps keep materials
There are 2 main types of vaporization:
evaporation and boiling.
Examples of amorphous solids
glass, butter, clay, plastics, Jello, and rubber, caramelos (dulces)
Examples of viscosity
honey, oil, molasses, syrup and body lotion.
A change from solid to liquid...
involves an increase in thermal energy
The melting point of pure water is...
is 0 Celsius at sea level.
water vapor
is a colorless liquid
Condensation
is the change in state from a gas to a liquid.
Freezing
is the change in state from liquid to solid.
Melting
is the change in state from solid to liquid.
When dry ice becomes a gas...
it cools water vapor in the nearby air, the water vapor then condenses into a liquid, forming fog near the dry ice.
At a solid's melting point...
its particles vibrate so fast that they break free from their fixed positions.
When the temperature of a gas at constant pressure is decreased
its volume decreases.
When the temperature of a gas a ta constant pressure is increases...
its volume increases.
Using dry ice is a way to...
keep the temperature low when a refrigetar is not available.
kPa
kilopascals
mm of Hg
milímetro de mercurio
Examples of crystalline solids:
minerals, salt, sugar and snowflakes
Pressure is measured in
mm of Hg, kilopascals, atm y Torr
Condensation occurs when...
particles in gas lose enough thermal energy to form a liquid.
Particles of a solid as it sublimes
particles of a solid do not pass through the liquid state as they form a gas
Charles' Law
pressure vs. volume, how does pressure affect the volume of a gas.
Properties of liquids
surface tension and viscosity.
Boyle's Law
temperature vs. volume, how does temperature affect volume.
Volume
the amount of space that matter fills.
In crystalline solids...
the melting occurs at a specific temperature.
When the temperature is decreased
the pressure of the gas decreases.
When the temperature of a gas at constant volume is increased,
the pressure of the gas increases.
The freezing point of water is...
the same as the melting point 0 Celsius.
In the 1600's...
the scientist Robert Boyle carried out experiments to try to improve air pumps. He measured the volumes of gases at different pressures. The experiments showed that ga, volume and pressure were related.
Melting point
the temperature at which a substance changes from a solid to liquid.
Chemists use boiling points...
to help identify unkown substances.
Torr
unidad de presión
When water boils...
vaporized water molecules form bubbles below the surface, they rise and eventually break the surface of the liquid.
example of surface tension:
water droplets on leaves
Example of freezing:
water increases volume
