C4

Particle   mass   charge          

electron  0.005   -1

nuetron      1      no charge 

proton        1       +1

•   electron fill shells around a atom
• elements with a full outer shell are MORE STABLE
• 1st shell = 2 2nd shell = 8 3rd sell = 8
• atoms can gain or lose electrons to gain a full outer shell
• metals lose electrons to orm POSITIVE ions
• non-metals form negative ions
• whe they have a charge they are ions NOT atoms
• ionic compounds form crystals as they have a giant lattice structure 
• ionic compounds do not conductb electricity when solid but do when molten because they ions can move

• used for identification
• some elements emit distinctive colours when heated ina flame
• the light gives a UNIQUE spectra
• can be used to discover new element 

when _____ is heated the colour is

Lithium (Li) = red

Sodium (Na) = orange/yellow

Potassium (K) - purple/lilac

The nucleus of an atom:

• middle of the atom
• contains protons&neutrons
• positive charge cause of protons
• almost wjole mass of atom is in the nucleus
• tiny compared to rest of atom

The electrons of an atom:

• move around the nucleus
• negativlycharged
• tiny but cover alot of soace
• volume of orbits determines size of atom
• virtually no mass
• arranged in cells are nucleus

number of protons equals number of electrons
neutral atoms have no overall charge

• the periodic tale is arranged by ascending proton number
• non-metals are towards the LEFT hand side of the periodic table where as the metals are central/to the RIGHT
• groups go UP periods go DOWN
• research who Mendeleev, Newlaids & Dobereiner are (inventors of the periodic table)
• understand how  Mendeleev used the periodic table to predict the existence of unknown elemts 

GROUP 1:

lithium, sodium, potassium, rubidium, caesium & francium

• as you go DOWN group 1 the alkali metals become MORE R EACTIVE, this is because the outer electron is more easily lost because its further from the nucleus
• they have a HIGHER DENSITY, because they have more mass  =  0.53 g.cm
• they have a LOWER MELTING POINT =  180.5 °C
• they have a LOWER BOILING POINT =   1342 °C
• group 1 are highly reactive due to their atomic structure and react highly with water

When lithium, sodium or potassium are out in water they react vigorously, they move around the surface, fizzing. They produce hydrogen, potassium gets hot enough to ignite it, this reaction makes an alkaline solution.

the balanced symbol equation of this is:

2Na(s) + 2H²0(1) > 2NaOH(aq0 + H²(g)

2K(s) + 2H²O(1) > 2KOH(aq) + H²(g)

GROUP 7: chlorine, bromine, iodine & astatine 

• they all have SEVEN outer electrons, this makes them higly reactive.asyou go DOWN group 7 they come LESS REACTIVE, because the outer electrons are futher from nucleus and so additional electrons are attracted less strongly
• have a HIGHER MELTING
• have a HIGHER BOILING POINT

• Fluorine is a very reactive, poisonous yellow gas at room temperature
• Chlorine is a fairly reactive, poisonous dense green gas at room temperature
• bromine is a dense, poisonous red-brown volatile liquid at room temperature and forms a red-brown gas.
• Iodine is adark grey crystalline solid at room temperature or a purple vapour

balanced symbol equation:

Cl² + 2KL(aq) > I(aq) + 2KCL(aq)

CL²(aq) + 2KBr(aq) > BrV(aq) + 2KCl(aq)