Mixtures and Matter Flashcards
Define particle
Particles are the smallest identifiable part of matter. The amount of space between these particles determines the state of matter of a substance.
Does an atom have charge? Why or why not?
An atom has no charge. This is because the number of protons (positive) is equal to the number of electrons (negative).
eg: 3 protons = +3
3 electrons = -3
3-3 = 0
What is the atomic number of an atom?
The number of protons it has.
What is the mass number of an atom?
The number of nuclear particles (protons and neutrons) in an atom (added together).
What are Ions?
Ions are charged atoms.
What happens when atoms gain and lose electrons?
Gain an electron - negatively charged
Lose an electron - positively charged
How are electrons arranged?
Electrons are arranged in fixed shells/orbits around the nucleus.
How many electron shells are in an atom?
The first 20 elements use only up to 4 shells:
Shell 1 - up to 2 electrons
Shell 2 - up to 8 electrons
Shell 3 - up to 8 electrons
Shell 4 - can contain more but only 2 electrons are added to it up to element number 20
What is diffusion?
Diffusion is the movement of particles from an area of high concentration to an area of low concentration, until the concentration is equal.
How do solids, liquids, and gases diffuse?
Solids at room temperature do not diffuse, liquids can diffuse through other liquids they can mix with. Gases readily diffuse with gases.
What is the difference between a solute and solvent?
Solute - substance being dissolved
Solvent - the liquid that dissolves the solute
What type of mixture is a solution?
Homogeneous.
What is solubility?
The measure of how well a substance dissolves in another substance (1 litre of solvent)
How does temperature affect solubility?
The warmer the solvent, the higher the solubility.
Define the term ‘filtrate’
The liquid that moved through the filter paper into the beaker.
What is decanting?
Decanting is allowing a mixture of two substances with different densities to settle and separate by gravity. Once this has happened, the lighter substance can be poured off.
physical property: DENSITY
Molecule
A group of the same/different atoms bonded together.
Element
a substance made up of only one type of atom. NOT CHEMICALLY BONDED
Compound
a substance made of two or more elements chemically bonded together
Mixture
Two or more substances that are not chemically combined
Pure Substance
A substance made up of only one type of atom/molecule.
Chromatography
A scientific technique used to separate a mixture of two or more different coloured pigments.
physical property: PARTICLE SIZE
How do pigments separate in Chromatography?
The pigments separate because they have different solubility in a solvent. The more soluble pigments are carried faster and therefore further by the rising solvent.,
What does heating metals cause the metals to do?
Heating metals causes the particles in the solid to vibrate faster, resulting in the gaps between particles increasing - expanding the solid.
Define Solution
A mixture where the solute is evenly distributed among the solvent.
Define convection
Convection is the movement of particles from an area of higher temperature to an area of lower temperature. As particles gain energy, they become less dense and rise.
Define conduction
Conduction occurs when particles collide with each other and transfer heat energy.
Use particles to classify matter as pure substances and mixtures
A pure substance is made up of only one type of atom or molecule. A mixture is a combination of two or more substances that are not chemically combined.
Define soluble
When a solute dissolves in a given solvent
Define insoluble
When a solute does not dissolve in a given solvent
Define saturated
When no more of a solute can dissolve in a solution
What does it mean when a solution is ‘concentrated’ or ‘dilute’
Concentrated solution: A concentrated solution is one in which there is a large amount of solute present in a mixture.
Dilute solution: A dilute solution has a little amount of the solute compared to the solvent.
Concentrated solutions have more solute particles than dilute solutions.
What happens when you heat a solution?
When a solution is heated, heat energy spreads the solvent atoms further apart, allowing the solute to dissolve in between.
On further heating, the components of the solution separate. The solvent evaporates, leaving behind the hot solute. (if solute is salt: na cl atoms move closer together and form salt crystals)
Chemical change
a change where a new substance is formed
Physical change
a change where the form of a substance changes, but not its chemical composition
Describe filtration
During the process of filtration, the filter paper allows the liquid to pass through, while trapping the dirt and bigger particles in the funnel that the paper has created.
physical property: PARTICLE SIZE
Describe distillation
In distillation, liquids are evaporated, and then heat is taken away in order for the gas to condensate and take its form as a pure liquid
physical property: BOILING POINT
Describe evaporation
In evaporation, heat is added to a liquid in order for its molecules to gain energy, move faster, and spread further away to turn into a gas.
physical property: BOILING POINT
Describe magnetism
In mixtures that contain a magnetic substance (e.g: sand and iron) when a magnet is held near, all the magnetic particles cling to the magnet, separating the two substances.
physical property: whether the substance is MAGNETIC
What are physical properties
Physical properties can be observed or measured without changing the composition of matter.
Examples:
appearance, texture, color, odor, melting point, boiling point, density, solubility,
What is heat energy?
Heat energy is created by the movement of tiny particles.
What is temperature?
Temperature is the measure of the amount of heat energy in a substance.
Describe what happens when a substance is heated
heat energy is added,
particles move around faster,
average kinetic energy increases,
and temperature goes up.
Describe what happens when a substance is cooled
heat energy is removed,
particles move around slower,
average kinetic energy decreases,
and temperature goes down.
Solid to Liquid
Melting
Liquid to Gas
Evaporation
Solid to Gas
sublimation
Gas to solid
Deposition
Liquid to solid
freezing
Gas to liquid
condensation
What is thermal expansion?
Thermal expansion is the tendency of matter to change in volume in response to a change in temperature.
