Term | Definition |
Pure Substance | Matter that only contains one kind of particle |
Mixture | Matter that contains more than one kind of particle |
Element | A pure substance made up of two or more different elements that are chemically combined. |
Compound | A pure substance that cannot be broken down into simpler parts by chemical methods. |
Physical property | A substanc that can not change its scent or type of substance. Can be observed an measured without changing its identity |
Chemical property | Ability for a substance to change or react and from a new substance. |
Physical change | -change substance back
-go from liquid to solid
-doesn't produce new substance
-doesn't change original substance |
Chemical Change | -Can't be reversed
-Forms a new substance
-Bubbles
-Odour changes |
Viscosity | The resistance of liquid to flowing. Applies to liquids only. |
Form | The shape of an object |
Texture | The way a substance feels |
Hardness | The resistance of a substance to be scratched. |
Ducktivity | The ability to be stretched into a wire. Applies to metals and other solids. |
Malleability | The ability of a substance to be hammered into a thin sheet. Applies to metals and other solids |
Conductivity | The ability of a substance to transmit heat, sounds, or electricity. |
Brittleness | The ability of an object to break apart or shatter easily. |
Solubility | A solid (solute) mixing with a liquid (solvent)to make a solution (mixture) |
Democritis | 400 AD
Came up with atomas (smallest thing possible on Earth) |
John Dalton | 1800
Came up with modern atomic theory and that the atom was a round ball |
J.J Thompson | 1897
Discovered electrons and made the cathode ray tube experiment:
one positive electron in the middle with four negatives around it. |
Ernst Rutherford | 1907
Discovered nucleus and created the gold foil experiment: Atom was not round and had negative electrons floating aorund the one positive in the centre. |
Neils Bohr | 1912
Discovered orbitals that the electrons travel on |
James Chadwick | 1932
Discovered neutron (no electric charge but has negative charge) |
Atom | The basic unit of a chemical element, smallest thing on Earth. |
Electron | Subatomic particle that is found in all atoms (negative charge) |
Subatomic Particle | A body having finite mass and internal structure |
Nucleus | DNA holder of a cell. Central and msot important part of cell. Found in atoms |
Proton | A subatomic particle occuring in a nucleus (positive charge) |
Neutron | Subatomic particles, similiar to a proton bu without electric charge. |
Alkali Metals | React rapidly when exposed to air or water. Low melting points and very soft. |
Alkaline Earth Metals | Highly reactive but less than alkali metals. Produce bright, colourful flames. Used in fireworks |
Halogens | Most reactive non metals. Extremely corrosive. Fluorine can be used to etch glass. Chlorine as a gas produces serious respiratory problems. Bromine causes serious skin burns. |
Noble gases | Non-reactive
Odourless, colourless
Produce interesting colours when excited by electricity |
Periods | Horizontal rows from groups 1-7 on the periodic table. |
Groups | Vertical rows on periodic table |
Metal | Shiny, ductile
Conductors of heat and electricity |
Non-metal | Bull and brittle
Poor conductors
Good insulators |
Metalloid | |
Ion | positively or negatively charged atom or molecule. Atom becomes an Ion when an atom loses or gains electrons |
Cation | Positively charged ion |
Anion | Negatively charged ion |