& chemistry MODULE FIVE IONIC BONDING CHEMICALS IN THE ATMOSPHERE The earth is surrounded by an atmosphere made up of many different substances, some of which are clement and some of which are compounds too. Air contains a number of different gases, with certain concentrations of these varying from and so are usually given for dy air. MOLECULAR COMPOUNDS Most non-metal clements are molecular, and most of them are diatomic, meaning they go around in Examples of these are N₂, Cl₂, O₂ God Brs. Most compounds between non-metals are also molecular, eg. H₂O, CO, and Net All of these substances have very strong covalent bonds between the atoms, but much weaker forces holding the molecules together. It is these 'intermolecular borts that break when boiled or heated, not the covalent ones. And because the weak intermolecular bonds break so easily, they have low melting points & boiling points. compound formuта HEL CH гамасат MP/ -115 BP/L -45 The easiest way to represent covalent bonds is to use either a 200 or a 3D molecular diagram. COVALENT BONDING HIGHER Covalent bonding is when two non-metal atoms share a pair of electrons in the outer electron-shell in order to completely fill it (usually with eight electrons). Most importantly, covalent bonds are very strong. H CL The strong bond between atend as a result of this is called electrostatic attraction between the posative nuclei and the negative electrons. Sometimes an atom is part of multiple bonds like carbon dioxide, in which one carbon atom is covalenty bonded to two oxygen atoms. From When metals react with non- metals, electrons are transferred the metal to the non-metal, creating an ion. The resulting compound is an ionic compound. The metal and non-metal are charged [+] and (-) respectively There is a strong electrostatic force of attraction between the twa oppositely charged iors called an ionic bond. Ionic compounds arranged in a lattice form crystals, Lise in sodium chloride (Nallz). Because of the strong bond, lots of energy is needed to break them and so ionic compounds have high MPs and BPs. They do not, however, conduct electricity because the lans are firmly held in place, which means they cannot more to conduct an electrical current. As a liquid they are free to move, and therefore do conduct electricity. Diamond and Graphite are good examples of how covalent bonds differ within compounds. Diamond has strong Covalent bonds througnoud unlike Graphite, which has strong bonds between atoms but not between layers, and as a result it Flakes easily- THE LITHOSPHERE All solid matter on Earth is part of something called the lithosphere, composed of the crest and the man He ELECTROLYSIS-STEP BY STEP () 1- Break up the Stuchure, through seating or dissolving. 2- Place the electrodas in pull the ions opart. In the example of copper chloride, all the positive metal lons (the the negative ions (C) go to the anada copper) go to the cathode, (anods) HANTLI CHIS hydrogen chlonde (HCL)