Chemistry

Atom

It is the smallest particle of matter that cannot be broken down, destroyed or created, they make up everything, to small to be be observed and inside them there are sub atomic particles.

Sub atomic particles

Are the things that make up an atom including a nucleus, electron shell, electrons, protons and neutrons.

Protons

Are positively charged subatomic particles found in the nucleus of an atom.

Neutrons

Are neutral (no charge) subatomic particles found in the nucleus of an atom, balancing the positive charge of protons.

Electrons

Are negatively charged subatomic particles that orbit the nucleus of an atom in electron shells.

Electron shell

The regions around the nucleus of an atom where electrons are likely to be found

Element

a substance that consists of only one type of atom and cannot be broken down into simpler substances.

Periodic Table

a tabular arrangement of the elements organised according to their chemical and physical properties.

Atomic Symbols

Abbreviations used to represent chemical elements, consisting of one or two letters.

Atomic Number

the number of protons found in the nucleus of an atom, which determines the element's identity.

Mass Number

is the mass of the atom, this is worked out by adding up the sub atomic particles inside the nucleus

Groups

Is the vertical columns which consists of elements that behave in similar chemical ways

Periods

The horizontal rows

Molecules

Are groups or two or more atoms that are bonded together, the atoms can be the same element or different.

Molecular Element

An element that exists as a molecule

Compound

Are made of more than one atom that are chemically bonded together, consisting of different elements.

Lattices

consist of compounds in an alternating continuous structure.

Mixtures

Is a combination of substances that can be physically separated. Cannot be represented by a chemical formula since the substances aren’t chemically combined.

Chemical Formulas

shows the elements present and how many there are in a combination eg H2 for hydrogen

Metals

a substance that is lustrous, good conductors of heat and electricity, malleable, ductile, have high melting points and boiling points

Non metals

Are elements that do not have the set of properties common to all metals. Some are coloured brittle and they all have a large range of melting points and boiling points.

Metalloids

Elements with properties of both metals and nonmetals, while most properties are considered un-metallic they still conduct electricity. Three of the metalloids are semiconductors.

Semiconductors

only conduct electricity in a certain way under certain conditions.

Physical Changes

Is when a substance still consists of the same particles but it looks different due to changes in physical properties such as shape, size, and state. It is reversible

Chemical Changes

When there is a reaction and a new substance is produced, the atoms have been moved around into new arrangements. It is not reversible.

Ways to Identify a Chemical Change

Permanent change in colours, change in temperature, production of light or sound, disappearance of a solid, formation of a new solid or gas (fizzing or a new odour)

Properties

Adjectives that describe the characteristics of a substance, including its appearance, behavior, and composition.

Melting

Solid to liquid

Evaporation

Liquid to gas

Solidification/Freezing

Liquid to solid

Condensation

Gas to liquid

Deposition

Gas to solid

Sublimation

Solid to gas

Lustrous

Shiny

Ductile

Can be drawn into wire

Malleable

Can be beaten into a new shape

Brittle

Breaks easily under stress or pressure

Reactants

The substances that react with eachother

Products

The new substance that is formed by a reaction

How did Mendaleev organise the periodic table

He organised it in order of atomic weight in row and the elements on the same column had similar properties.

Matter

Anything that has mass and takes up space.

Decomposition Reaction

A reaction with only one reactant

Solubility

The ability of a substance to dissolve in a solvent

Hardness

a substances resistance to scratching and deformation

Lustre

The way a surface reflects light, contributing to its appearance as shiny or dull.

Conductivity

The ability of a material to conduct electricity or heat.