CHEMISTRY P1 Flashcards
Elements
All atoms are the same type
Compounds
2 or more elements chemically bonded together
Mixtures
2 or more compounds not chemically bonded together
Early model
Tiny indivisible spheres
Plum pudding model
Atom was sphere of positive charge with negative electrons spread throughout it
Rutherford and marsden experiments
alpha scattering experiments: Positive alpha particles fired at a piece of gold foil.
Most went right through it proving the atom was mostly empty space.
some were deflected proving that atom had a positive nucleus
Neils bohr
Discovered that the electrons orbit the nucleus of the atoms at specific distances in shells
James Chadwick
Discovered there was a neutron in the nucleus
Group 0
noble gases: Non metals that aren’t very reactive. have a low density and a stable arrangement pf atoms. boiling point goes down in the group
Group 1
Alkali metals; metals with a low density. Reacts with non metals to form ionic compounds. Violently reacts with water to release hydrogens.more reactive as they go down the group because less attraction from the nucleus so other shell is easily lost
Group 7
Halogens: Non metal. diatomic atoms. Reacts with metals to form ionic compounds. boiling points goes down with groups. les reactive os you go down the group
Cations
lose electrons. metals. positive charge
anions
gained electrons.non metals.negative charge
Ionic bondings
opposite charges attract. Electrostatic attraction.have a high boiling and melting point and boiling point. strong electrostatic forces.can conduct electricity when molten or in an aqueous solution as the ions are free to move
