Summary C1 Atomic Structure and the Periodic Table

Atomic Structure and the Periodic
Table C1
Atoms
 radius of 0.1 nanometres (1000x times smaller than a micro metre)
 Proton is positive has a RAM of 1
 Neutron has no charge and has a RAM of 1
 Electron is negative has a RAM of virtually 0
 whole mass concentrated in nucleus
 volume of electron’s orbit determines the size of atom
 number of protons = number of electrons

Elements and Isotopes
 number of protons in nucleus decides what kind of atom it is
 ISOTOPES- same element with different number of neutrons
 RAM is an average mass taking into account different masses and abundances of all the isotopes




Compounds
 Substances formed from two or more elements
 Making bonds involves atoms giving away, taking or sharing electrons
 METAL ATOMS LOSE ELECTRONS AND BECOME POSITIVE IONS
 NON-METALS GAIN ELECTRONS AND BECOME NEGATIVE IONS
 Non-Metal and Non-metal bonding is called Covalent bonding-
SHARE ELECTRONS
 Non-metal and metal bonding is IONIC BONDING- TRANSFER
ELECTRONS
 Properties of compounds are totally different from original
elements

Mixtures
 Mixtures are easily separated by physical methods
 Mixtures have no chemical bond
 Mixtures: air, crude oil, milk, seawater etc

Chromatography
 Used to separate dyes and ink
1. Draw a pencil line near the bottom of a sheet of filter paper
2. Add a spot of ink to the line and place the sheet in a beaker of solvent (water) {other
solvents can be used but it depends on what is being tested, EG ethanol}
3. Make sure the ink isn’t touching the solvent
4. Put a lid to stop evaporation