C2-bonding

• ions are made when electrons are transfered
• ions are charged particles that can be single or a group of atoms
• when atoms lose or gain electrons to form ions its to form a full outer shell (stable electronic structure)
• when metal ions form they lose electrons
• non-metal ions gain electrons
• when non mentals form ions they gain electrons into their outer shell to form negative ions
• the number of electrons lost or gained is the same as the charge e.g if 2 electrons are lost the charge is -2
• group 1 and 2 elements are metals and they lose electrons to form positive ions ( CATIONS )
• group 6 and 7 elements are non metals and they gain electrons to form negative ions (ANIONS)
• Elements in the same group all have the same number of outer electrons
• • group 1 elements form +1 ions
• • group 2 elements form 2+ ions
• • group 6 elements form -2 ions
• group 7 elements form -1 ions
• ionic bonding happens between a metal and a non metal
• in ionic bonding the metal atom loses electrons to form a positively charged ion and the non metal gains these electrons to form a negativly charged ion
• in ionic bonding these oppositely charged ions are strongly attracted to one another by ELECTROSTATIC FORCES. this is called an ionic bond
• • dot and cross diagrams show the arrangement of electrons in an atom or ion
• each electron is repesented by a dot or a cross
• the aim is to form two full outer shells 2,8,8
• ionic compounds have a structure called a giant ionic lattice
• the ions form a closely packed REGULAR ATTICE arrangement and they are very strong ELECTROMAGNETIC FORCES OF ATTRACTION between OPPOSITLY CHARGED ions in all directions in the lattice
• • a single crystal of sodium chloride (table salt) is ONE GAINT IONIC LATTICE
• • ionic compounds all have similar properties
• ionic compounds all have high boiling and melting points due to many strong bonds between ions
• ionic compounds when they are solid the ions are held in place so the compounds CANT conduct electricity
• when ionic compounds melt the ions are free to move and carry out electric charge
• some ionic compounds dissolve in water . the ions separate and are all free to move in the solution so they`ll carry electric charge
• finding empirical formula of a dot and cross diagram, count up how may atoms there are of each element
• ionic bonding is transfer of electrons
• covalent bonds is sharing electrons
• covalent bonds is between non metal atoms bonding together to share a pair of electrons
• covalent bonds positively charged nuclei of the bonded atom s are attracted to the shared pair of electrons by a ELECTROSTATIC FORCE making covalent bonds VERY STRONG
• covalent bonds only share electrons in their outer shells ( HIGHEST ENEGY LEVEL )
• each covalent bond provides one extra shared electron for each atom
• covalent bonds happen in compounds of non metals ( e.g. H20 ) and in non metal elements (e.g. cl2 )
• covalent bonds in dot and cross diagrams

  
• ways of drawing covalent bonds

  
• substances containing covalent bonds usually have simple molecular structures
• the atoms within molecules are held together by very strong covalent bonds