Particle and Mixtures

What are the 3 things that affect how strong the forces of attraction are between the particles of the material

Material-Temperature-pressure

Characteristic of Solids

-Strong forces of attraction between particles (hold them close in fixed positions)

-Definite shape/volume

-Particles vibrate about their positions (the hotter, the more vibrations)

What causes the strong force of attraction of a solid

Regular lattice movement

What causes the increase in temperature of a solid

Solids expand slightly

Characteristic of Liquids

-Weak force of attraction between particles (randomly arranged, free to move)

-Definite volume

-Not definite shape (flow to fill bottom of a container)

-Particles are constantly moving with random motion (the hotter the faster)

What causes the increase in temperature of a liquid

Liquids expand slightly

Characteristic of Gases

-Very weak force of attraction between particles (free to move, far apart)

-Dont keep a definite shape(always fill the container)

-Not definite shape

-Particles are constantly moving with random motion (the hotter the faster)

How do the particles in gases move

In straight lines

What do gasses do when heated

Expand or their Pressure increases

What is Physical change

A change that affects the form or appearance of a substance

What is Chemical change

A change in which one or more new substances are formed because the atoms are rearranged to make different substances.

What happens when a State is heated

-Particles gain more energy (kinetic)

-Particles vibrate (solid) more or move faster(liquid)

-At a certain temp (point) particles have enough energy to break free

-The substance changes state

What does the vibration of the particles do when a solid is heated

weakens the force that holds the solid (creates expansion)

Solid to Liquid

Melting

Liquid to Solid

Freezing(solidification)

Liquid to Gas

Boiling (or evaporation)

Gas to Liquid

Condensation

Solid to Gas

Sublimation

Gas to Solid

Deposition (or desublimation)

Definition of Diffusion

Diffusion is the net movement of particles from an area of high concentration to an area of low concentration until they are evenly spread out.

Solution

A mixture of Solvent and Solute

Solution

a mixture of a solute and a solvent that does not separate out

Solute

the substance being dissolved

Solvent

The liquid it is dissolving into

Saturated Soution

Solution where the maximum amount of solute has been dissolved

no more solute will dissolve in the solution

Solubility

Measure of how much Solute will dissolve in a Solvent

Solubility is measured in?

Grams of solute per 100 grams of solvent

Trend of solubility of Solids

Increases as the temperature increases

Filtration

A method to separate an insolube solid from a liquid using filter paper
(Insolube solid + liquid)

Evaporation

A method to obtain a solube solid by heating a solution until the solvent evaporates

(Soluble solid + liquid)

Crystallisation

A method to produce pure crystals from a solution by evaporating some solvent and then cooling the solution

(Soluble solid + liquid)

Simple Distillation

A method to separate a solvent from a solution by boiling and condensing it

(Solvent + dissolved solid)

Fractional Distillation.

A method to separate miscible liquids with different boiling points

(Two or more liquids)

Paper Chromatography

A method to separate soluble substances based on how far they travel on paper

(Mixtures of soluble coloured substances)

Magnetic Separation

A method using a magnet to separate magnetic materials from non-magnetic materials

(Magnetic + non-magnetic solids)

Sieving

A method that separates solids based on particle size using a sieve
(Solids of different sizes)

Decanting

A method that separates a liquid from a settled solid or another liquid by carefully pouring off the top layer

(Solid + liquid or immiscible liquids)

Separating Funnel

A method that separates immiscible liquids using their different densities

(Two immiscible liquids)

Centrifugation

A method that separates very fine suspended solids from a liquid by spinning the mixture rapidly

(Fine insoluble solids + liquid)

Calculate Solubility

Solubility = Mass of solute dissolved​ / Mass (or volume) of water ×100​

(If using water, 1 cm³ of water ≈ 1 g of water)

Atoms are made of

3 subatomic particles (protons, neutrons and electrons)

Definition of Atom

An atom is the smallest particle of an element that can exist and still has the chemical properties of that element.

Key facts of Atoms

Everything is made of atoms.

Atoms are the building blocks of all matter.

Each element is made up of only one type of atom.

Atoms are extremely small (about 0.1 nanometres in diameter)

Protons

-Heavy (relative mass = 1)

-Positive charge(relative charge = +1)

Neutrons

-Heavy (relative mass = 1)

-Neutral (relative charge = 0)

Electron

-Hardly any mass (relative mass = 0.0005)

-Negatively charged (relative charge = -1)

Nucleus

-Middle of the atom

-Contains protons and neutrons

-Postive charge (protons)

-Almost whole mass in nucleus

-Nucleus is tiny

Electrons

-Move around the nucleus in energy levels called shells

-Negative charge

-Tiny but their orbitals cover a lot of space

-The size of their orbitals determines the size of the atom

-Electrons have virtually NO mass

Top number in period table

Mass number

Bottom number in period table

Atomic number

What are the 2 subatomic particles that will ALWAYS equal in a neutral atom

Protons and Electrons

If some electrons are added or removed then the atom becomes…

Charged therefore it is an Ion

How to find neutrons

Substract Mass number with Atomic number

Ion

An ion is an atom or group of atoms that has gained or lost electrons, giving it an overall electrical charge.

Molecule

A molecule is a group of two or more atoms chemically bonded together

(Atoms can be the same or different elements)

Compound

Two or more different elements chemically bonded together

(Atoms must be different elements)

Examples of Molecules (same element)

-O₂ (oxygen)

-H₂ (hydrogen)

-N₂ (nitrogen)

Molecules and Compounds

-H₂O (water)

-CO₂ (carbon dioxide)

-NH₃ (ammonia)

(These are both molecules and compounds because they contain different elements)

Covalent Compound

They form when non-metals share electrons

-✅ Are compounds

-✅ Are made of molecules

Ionic Compound

-They form when a metal transfers electrons to a non-metal, creating positive and negative ions in a giant lattice

-✅ Are compounds

-❌ Are not molecules

Miscible

Used only for liquids

Means two liquids mix completely

Immiscible

Two liquids do not mix and form separate layers

Isotopes

Different atomic forms of the same element

which have the same number of protons but different numbers of neutrons

Relative atomic mass (Ar)

Relative atomic mass (Ar) is the weighted average mass of an element's atoms, taking into account the abundance of each isotope

What is the reference standards for isotopes

Carbon-12

(Compared with 1/12 of the mass of a carbon-12 atom)

Relative abundance

Relative abundance is the percentage or proportion of atoms of a particular isotope in a naturally occurring sample of an element

Average mass

An average mass is the mass you get when you combine the masses of all the atoms and take the mean

Formula for relative atomic mass

Relative mass of isotope x relative abundance + Relative mass of isotope (2) x relative abundance (2)/sum of relative abundance

Element

Consists of one type of atom only