BMAT Ninja Chemistry- Chemical Bonding, Structure + Properties and Groups

What is an element a Substance that contains only ONE type of atom. What is a compound 2 or more elements chemically combined What is a mixture A combination of two or more substances that are not chemically combined (can be physically separated) What is the structure of ionic compounds giant ionic lattice with a regular arrangement How are the ions held together in ionic bonding? - by strong electrostatic forces of attraction Why do ionic compounds have high melting and boiling points? electrostatic forces require lots of energy to overcome Can ionic compounds conduct electricity? - when molten or in aqueous form - ions are free to move around and carry an electrical current What does a covalent bond represent one shared pair of electrons Why do macromolecules have high melting and boiling points? - covalent bonds requires lots of energy to break Why can graphite conduct electricity? -layer of delocalised electrons between the sheets of atoms can move and carry charge Why is graphite slippery - weak intermolecular forces between layers are easily overcome so layers can slide over each other Structure of metals - positive metal ions surrounded by a sea of delocalised electrons (which come from the outermost electron shells of the metal atoms) Why are metals good conductors of electricity and heat? delocalised electrons are free to move through structure carrying heat and charge