Chapter 3 - Explaining Physical Changes Flashcards
What are 3 main states of matter?
The three states of matter are Solid, Liquid and Gas.
What are the properties of a solid?
A solid has a fixed shape.
It can’t flow.
It can’t be compressed.
What are the properties of a liquid?
A liquid takes the shape of its container.
It can flow.
It can’t be compressed.
What are the properties of a gas?
It takes the shape of a container and fills it.
It can flow.
It can be compressed.
Why does a solid have a fixed shape?
They have a strong and attractive intermolecular force between them which holds them in their position. They also have a regular fixed pattern.
Why does the liquid take the shape of it container?
It takes the shape of its container because it is arranges in a random pattern allowing them to move and they have a very weak intermolecular force.
Why does gas take the shape of its container and fill it?
Gas takes the shape of the container and fill it because it has a random pattern and is spaced about as well as have a very weak intermolecular force.
Why can’t solids flow?
Solids can’t flow because they have strong intermolecular forces and a regular fixed pattern. As well as that, they are very close to each other.
Why can liquids flow?
Liquids can flow because they can move around each other.
Why can gases flow?
Gases can flow because they can move very quickly around each other and are also very spaced apart.
Why can’t solids be compressed?
Solids can’t be compressed because they have very strong intermolecular forces and are very close to each other.
Why can’t liquids be compressed?
Liquids can’t be compressed because they have strong intermolecular forces and are also very close to each other.
Why can gases be compressed?
Gases can be compressed because they have weak intermolecular forces and also are very spaced apart.
Malleable
Able to bend without breaking
Strength
The ability of a solid to withstand a force
Hardness
A measure of how easy it is to scratch a solid
Soluble
Able to dissolve (sometimes in water)
Conduct
Transfer of heat or electrical charge by passing on energy to nearby particles
Alloy
Mixture of metals
Hypothesis
An idea that explains facts or observations and is the basis for experimentation (X depends on Y)
Brownian motion
Movement of solid particles caused by collisions with liquid particles
Kinetic theory
Theory that all matter is made up of particles
Evidence
Information gathered in a scientific way which supports or contradicts a conclusion
Viscosity
The ability of liquids and gases to flow
Compressed
When particles are squashed together by force
Solubility
The mass of a solute that dissolves in a solvent at a particular temperature
Sublimation
When a solid turns straight into a gas without a liquid state
Melting point
The temperature at which liquid changes state to a liquid
Boiling point
The temperature at which liquid changes state to a gas
Latent heat
The heat energy needed to change the state of a substance
Evaporation
Change from a liquid to a gas at the surface of a liquid
Boiling
When a liquid changes state to a gas
Surface area
The area of the outside surface of an object
Thermal expansion
When particles in a solid or a liquid gain enough energy to occupy more space
Atom
The basic building block of an element that cannot be chemically broken down
Element
A substance made up of only one type of atom
Compound
Two or more elements that are chemically joined together such as water
Particle model
Used to explain the kinetic theory of solids, liquids and gases
What is viscosity?
Viscosity is a measurement of how resistant a fluid is to attempts to move through it. A fluid with low viscosity is said to be ‘thin’, while a high viscosity fluid is said to be ‘thick’
Why can gases be compressed?
There is space between the particles for them to move into
Why can gases flow?
The particles are able to move around each other.
Why does liquid take the shape of the container they are in?
The particles are able to move around each other and are arranged in a random pattern.
Why can’t liquids be compressed?
There is no space between the particles for them to move into.
Why can liquids flow?
The particles are able to move around each other.
Why can gases completely fill the container they’re in?
The particles are able to spread out and move quickly in all directions.
What is change of state?
A change of state is when solid turns into gas. It’s when a state changes to another state.
What is the difference between boiling and evaporation?
Boiling is when specific heat/temperature is applied whereas in evaporating, any temperature can be applied and it can take place at the surface of liquid.
What are factors that can affect evaporation?
Weather Surface area Positioning Strength of intermolecular forces Wind speed
What is density?
It is the mass of material per unit volume. It takes into account how heavy something is compared with its volume (how much space it takes up)
How do you work out density, mass and volume?
Density= Mass divided by Volume Mass= Density times Volume Volume= Mass divided by Density
What is concentration?
Concentration is the amount of substance dissolved in a solution per unit of volume.
How do you work out concentration?
Concentration= Mass (g) divided by Volume (L)
What happens to the total mass after any chemical reaction or physical change?
In any chemical reaction or physical change, the total mass after the reaction was exactly the same as the mass before.
What are chemical changes?
Chemical changes (reactions) are usually irreversible.
What signs would chemical changes have?
They have: Bubbles or fizzing Gets warmer... or colder Smells (nice or nasty) Noises (from loud bangs to quiet fizzing) Flames or sparks
What are examples of physical changes?
Solid to liquid= melting
Liquid to solid= freezing
Liquid or gas= evaporating
Gas to liquid= condensing
What is an emulsion?
An emulsion is a mixture of two liquids, (eg: oil and water), that don’t want to mix.
What is an emulsifier?
An emulsifier is a molecule that makes the two liquids (that don’t want to mix) mix together.
What is a colloid?
A colloid is when different states of matter are dispersed together.
What are foams?
Foams are a mixture of gas bubbles trapped inside a liquid.
What is a gel?
A gel is mixture of liquid particles flooding inside solid.
