17. Charles Law ‐ as the temperature of a gas goes up its volume goes up.
Matter and Its States
I. All matter is found in 1 of the 4 phases or states – solid, liquid, gas, and plasma.
A. No matter what state matter is in it has certain
physical and chemical properties.
B. Physical Properties are characteristics of a substance which can be observed without changing the identity of the substance.
i. Color, shape, size, mass, weight, phase, density, volume, and hardness are all physical properties
ii.When one of these is changes the substance is
still the same substance but it has gone through a physical change.
C.A physical change is when a substance’s physical
properties are changes but it still is the same substance.
1. A common physical change is a phase change – when a substance moves from one state of matter (phase) to another.
a. Water, ice and steam all look different but
chemically they are the same – H2O. They are different phases of the same substance.
b. Different phases of the same substance are
made of the same stuff – what make them different is how the little pieces are arranged and how much energy they have.
II. Solid – Solid is the state of matter where a substance has a
definite shape and a definite volume. Particles are tightly packed together and can only move by vibrating back and forth.
A. All solids share 2 important physical characteristics
1. They have a definite shape – a solids shape won’t
change on its own.
2. They have a definite volume - it won’t all of a
sudden shrink or get bigger.
B. In solids the particles are tightly packed and
arranged in an organized fashion. The particles are moving but they are so close they can only vibrate back and forth.
1. Some solids are arranged in a repeating pattern
of shapes called crystals – like salt or sugar crystals – they are all the same shape.
2. The particles of some solids can move a little bit
– these can change shape slowly. Glass is an example of this – if you look at an old window, the bottom is thicker than the top because the glass particles have slowly moved towards the bottom – gravity has pulled them down. These solids are called amorphous solids.
III. Liquid is the state of matter in which a substance has a
definite volume but NO definite shape. Particles have more energy than a solid but less than a gas. The particles slide around each other in an unorganized fashion and can change position.
A. All liquids share 2 important characteristics
1. No definite shape – they take the shape of the container
2. They do have a definite volume – you can’t make
a liquid take up less space – try squeezing water and it squirts out – doesn’t get smaller.
3. In a liquid the particles are touching each other
but they are not held in place like in a solid. They can change position and flow around one another. This is what allows a liquid to pour or flow out of a container. The amount of resistance the liquid has to moving is called its viscosity.
a. Viscosity is defined as a liquid’s resistance to flowing. Syrup has a high viscosity while perfume has a very low viscosity.
4. Particles in a liquid have more energy than in a solid – they move faster. But they have less than in a gas – they always have to stay in contact with each other – this is why a liquid has definite volume – it can’t be squeezed because the particles are already as close as they can be.
IV. Gas is the state of matter which has no definite shape and
No definite volume. Particles have more energy than a solid or liquid. Particles move around quickly and in no pattern – they spread out in all directions.
A. Gases share 2 important characteristics
1. They have NO definite shape – they spread out and fill the container
2. They have NO definite volume – they can spread out and take up more space or they can be squeezed into a container and take up less space.
3. In a gas the particles are flying around
quickly in all directions. This allows a gas to spread out through an area – like the odors from the cafeteria. The particles are constantly bouncing off of each other and their container. These collisions are what causes a gas to fill up and hold a balloon in a shape. Gas Pressure is the amount of force with which the gas is pushing against its container.
B. There are 2 laws that explain how a gas behaves
1. Boyle’s Law – it says that as the volume
of a gas goes down its gas pressure goes up and the reverse – as volume goes up pressure goes down. As you squeeze a gas into a smaller container it pushes harder on that container to get out!
2. Charles’ Law – it says that as the temperature of a gas goes up so does its volume. As you heat the air in a balloon it expands and takes up more space – the balloon gets bigger – like a hot air balloon. As you heat a gas the particles move faster and faster and spread out more – increasing the volume.
V. Plasma – state of matter in which the particles have the greatest amount of energy. Most of the universe is made of plasma, like stars, but very little is found on Earth.
A. SUBLIMATION is when a solid turns directly into a gas
skipping the liquid phase
1. Dry Ice is the best example of this - it changes from a solid to a gas, the fog, without ever becoming a liquid.
I. A substance is in a given phase based on the amount of energy its
particles have. The particles in a solid have less energy than particles of the same substance in the liquid or gas phase. Because of this it is POSSIBLE TO CHANGE A SUBSTANCE'S PHASE BY ADDING OR TAKING AWAY ENERGY (HEAT).
A. Phase change between a solid and a liquid.
1. MELTING is the changing of a solid to a liquid
a. Melting occurs when energy (heat) is added to a solid.
b. The temperature at which enough energy has
been added for the solid to turn into a liquid is called the MELTING POINT.
2. FREEZING is the changing of a liquid to a solid.
a. Freezing occurs when energy (heat) is taken away from a liquid
b. The temperature at which enough energy (heat) has been taken away from a liquid so that it can turn into a solid is called the FREEZING POINT.
c. The freezing point and the melting point temperatures are the same - for water it is O Celsius, 32 Fahrenheit. What you call it depends on which way the temp. is moving - going up = melting pt., going down = freezing point.
B. Phase change between a liquid and a gas.
1. VAPORIZATION is the changing of a liquid to a gas
a.When vaporization occurs because the liquid has gained enough energy (heat) to change to a gas it is called BOILING
b.Vaporization can also occur on the surface of a liquid - this is called EVAPORATION
c.The temperature at which enough energy (heat) has been added to the liquid to turn it into a gas is called the BOILING POINT.
2. CONDENSATION is the changing of a gas to a liquid
a. Condensation occurs when enough energy (heat)
has been taken away from a gas to turn it into a liquid.
b. The temperature at which enough energy has
been taken away so the gas can turn into a liquid is called the CONDENSATION POINT.
c. The boiling point and condensation point
temperatures are the same - for water it is 100 Celsius, 212 Fahrenheit.
d. What you call it depends on which way it is going -
up is Boiling Pt. down is Condensation Pt.
C. Change between a solid and a gas
1. SUBLIMATION is when a solid turns directly into a gas skipping the liquid phase
a. Dry Ice is the best example of this - it changes from a solid to a gas, the fog, without ever becoming a liquid.
2. DEPOSITION is when a gas turns directly into a solid skipping the liquid phase.
a. Frost is the best example of this – it changes from a gas, the air, into frost a, a solid without ever becoming a liquid.