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Physics & Chemistry 2nd ESO - Coggle Diagram
Physics & Chemistry 2nd ESO
MATTER
Atoms and molecules
MATTER: everything that has mass and takes up volume
ATOMS: the smallest particle in which matter can be split without losing its properties, also called the basic particle of matter.
Nucleus
Protons
Neutrons
Shells
Electrons
MOLECULE: a group of two or more atoms joined together by bonds
Examples
Sodium cloride (NaCl)
Water (H2O)
Ammonia (NH3)
SUBSTANCE (chemical substance): a form of matter which has specific composition and specific properties.
THE PERIODIC TABLE OF THE ELEMENTS
There are over 100 different types of elements
Only 90 can be naturally found on Earth.
Our body is made up of just 26 of them.
The elements are put in order according to the number of protons they have. This number is called the atomic number (Z) and is unique for each element (just like our ID card number).
By default toms are electrically neutral so No. protons = No. electrons.
There’s another important number called mass number (A), which equals the number of protons + the number of neutrons.
Each element is represented by a symbol consisting in one or two letters. The first is always capital while the second is always small.
Rows are called periods. The elements that belong to the same period have the same number of shells.
Columns are called groups or families. The elements that belong to the same group have the same number of electrons in their outermost shell.
BLOCKS
Noble gases
Halogens
Alkali metals
Alcaline Earth metals
Transition metals
Poor metals
Lanthanides
Actinides
Comparing elements
MASS: the higher the Atomic Number, the heavier the element.
DENSITY: within a family: the lower the position, the higher the density.
MELTING POINT: within a family: the lower the position, the lower the melting point.
Classification of matter
PURE SUBSTANCES: made of one substance
ELEMENTS: made of one type of atom (Fe, Au, H, O2)
COMPOUNDS: made of two or more types of atoms (H2O, CO2)
MIXTURES: made of more than one substance
HOMOGENEOUS MIXTURES: we cannot distinguish the substances/components they are made of (sea water, tap water, infusions, bronze, steel).
HETEROGENEOUS MIXTURES: we can distinguish the substances/components they are made of (oil+water, pizza, marble, wood)
ISOTOPES: variant of a particular chemical element which differs in the number of neutrons
SOLUTIONS (homogeneous mixtures)
Combinations
Gas-Gas: Air (N2+O2+CO2)
Gas-Liquid: Carbon Dioxide (CO2) in Soda
Gas-Solid: Hydrogen (H2) in Palladium (Pd) Metal
Liquid-Liquid: Gasoline (different hydrocarbons)
Liquid-Solid: Dental Fillings (amalgam: mixture of mercury with an alloy made of silver, tin, and copper solid particles)
Solid-Solid: Metal Alloys such as bronze (copper and tin) or brass (copper and zinc)
Soluble substances
Insoluble substances
Solute
Solvent
SATURATED SOLUTION: a point is reached in which no more solute can be dissolved in the solvent.
TEMPERATURE: the higher the temperature the faster the solute dissolves because there is more energy, so particles move faster and they mix more easily.
CONCENTRATION
PERCENT COMPOSITION BY MASS: the parts of solute per 100 parts of solution.
FORMULA: Percent by mass = (mass of the solute / mass of the solution) · 100
SEPARATING MIXTURES
Sieving
to separate a mixture of two solids which have different particle size.
Decanting or decantation
to separate a heterogeneous mixture of two liquids or a heterogenous mixture of a solid and a liquid.
Filtering or filtration
to separate a heterogeneous mixture of a solid and a liquid.
Evaporation
to separate a homogeneous mixture of a solid and a liquid.
Chromatography
to separate homogeneous mixtures.
MATTER AND ITS PROPERTIES
GENERAL PROPERTIES
Mass
Volume
SPECIFIC PROPERTIES: allow to distinguish different types of substances
Color
Hardness
Melting point
Boiling point
Density
PHYSICAL QUANTITIES: properties that can be measured.
Length
Mass
Time
INTERNATIONAL SYSTEM OF UNITS: SI
BASE UNITS
Length: meter (m)
Mass: kilogram (kg)
Time: second (s)
Electric current: ampere (A)
Temperature: kelvin (K)
Substance amount: mole (mol)
Light intensity: candela (cd)
DERIVED UNITS
Area: square meter (m2)
Volume: cubic meter (m3)
Speed, velocity: meter per second (m/s)
Mass density: kilogram per cubic meter (kg/m3)
STATES OF MATTER: the kinetic theory
SOLIDS
Particles...
Are close together.
Are arranged in a regular way
Cannot move from place to place
Can vibrate
As a consequence:
Solids cannot be compressed
Solids have a fixed shape and cannot flow
LIQUIDS
Particles...
Are close together
Are arranged in a random way
Can move around each other
As a consequence:
Liquids flow and take the shape of the bottom of their container
Liquids cannot be compressed
GASES
Particles...
Are far apart.
Are arranged in a random way.
Move quickly in all directions.
As a consequence:
Gases flow and completely fill their container.
Gases can be compressed.
CHANGES OF STATES OF MATTER
Solid -> liquid: melting/fusion (ice>water)
Liquid -> gas: vaporization (water>water vapor)
Gas -> liquid: condensation (water vapor>water)
Liquid -> solid: solidification (water>ice)
Solid -> gas: sublimation (coal, dry ice (solid CO2), air freshener)
Gas -> solid: deposition (frost)
COLLOIDS
FORCES & MOVEMENT
ENERGY
CHEMICAL REACTIONS
CHEMICAL AND PHYSICAL CHANGES
Chemical changes