Please enable JavaScript.
Coggle requires JavaScript to display documents.
Yr 10 Chem (Chemical Reactions (Combustion (Reactive metals such as…
Yr 10 Chem
Chemical Reactions
-
Decomposition
-
-
Some substances will only decompose when heated, this is known as thermal decomposition. Metal carbonates and metal hydrogen both undergo thermal decomposition when heated
Law of Conservation
The law of conservation sates that during a chemical reaction, atoms can not be created or destroyed
-
-
Combustion
-
-
Combustion is any chemical reaction in which a substance burns in oxygen to produce heat and light (exothermic) in some reactions the energy is converted into other forms of energy such as electrical
When reactions have limited oxygen it produces carbon monoxide and sooty carbon (incomplete combustion)
-
-
Chemical Bonding
Metallic bonding
Metallic bonding involves metal atoms giving up valence electrons and share them with all the other atoms in the metal (delocalised electrons) they all become positive atoms
There is now a strong force of attraction from the positive ions and the negative electrons, these forces of attraction hold everything together. This gives the overall metal strength and means that most metallic structures have high melting and boiling points
In metals, the atoms are bonded toegther by a 'sea' of electrons, in most metals the atoms are packed closely together
Metals are also good conductors of heat and electricity because the delocalized electrons can carry electrical current and thermal energy through the whole structure
Metals are also malleable this is due to its regular structure, which means it has layers and these layers can slide over one another because they are not fixed.
Characteristics
Ionic Compounds - only soluble in polar liquids, hard but brittle, high boiling/melting points
Covalent molecular - structures consist of molecules on their own. They have low melting and boiling points. The covalent bonds between the atoms within the molecules are strong
Metals - not soluble at all, hard and strong, high melting/boiling points, conduct electricity as liquids and solids
Covalent network - made from a network of repeating lattices of covalently bonded atoms. They often have high melting and boiling points and are insoluble in water.
-
Ionic compounds
Melting and boiling points are determined by the bonds holding the substance together and since there are a lot of bonds in an ionic compound the bond is really strong, this means more energy will be required to break those bonds and that energy is a high temperature
To conduct electricity you need charged particles that can move these could be ions or electrons, when ionic compounds are in there solid form everything is fixed and they can not conduct electricity, but when they are melted or dissolved in water, the ions of the compound are free to move about, and this movement of charged particles allows them to conduct electricity
Generally ionic compounds include tons of atoms not just a couple and the positive and negative ions altnerate so that each ion is attracted to each of those around it and if this happens in all directions it will form a 3D lattice
-
-