Please enable JavaScript.
Coggle requires JavaScript to display documents.
Science Chemistry Term 3 Year 9 (The periodic table (Metals (Ductile,…
Science Chemistry Term 3 Year 9
Substances
Element: An element is a unique substance (Type of atom) classified by the number of protons it has in the nucleus
Compound: a molecule made up of multiple elements
Mixture: when a solvent is dissolved into a solution. No new substance is created and the solvent can be separated from the solution.
Structure of the atom
Atomic number & Mass number
Mass number = Protons + Neutrons
Atomic mass is the average mass of all atoms of that element to exist
Mass number is the mass of a specific particle
Electronic configuration of an atom
2,8,8,2 (Max shells first 20)
Ions
Ions are charged atoms
Cations
Positively charged
Has lost electrons (more protons, positive)
Anions
Gains electrons (more electrons, negative)
Negatively charged
Ionic compound
The periodic table
Groups: Vertical sections on the periodic table
Periods: The horizontal sections in the periodic table
Metals
Ductile
Malleable
Shiny
Lustrous
Metalloids
Mostly like non metals
Semi-conductors (Conduct electricity under certain conditions)
Non- Metals
Brittle
Doesn't conduct electricity
Dull
Low melting/boiling point
Isotopes
Same number of protons and electrons, different number of neutrons
Radiation/Radioactive decay
Beta radiation
Can be stopped with foil
Gives off electrons
Neutron changes into a proton and an electron and becomes a new element
Gamma radiation
Most damaging
Happens after another type of radiation (alpha or beta) is released
Alpha radiation
Exposed every day
Can be stopped with paper
Least harmful
Alpha radiation particles are identical to helium nucleus
Isotopes decay when the ratio of neutrons to protons is too high. This is radioactive decay
Half-life: when 50% of the particle has degraded