IGCSE ICT Revision What is Hardware? Hardware is the physical parts of the computer system – the parts that you can touch and see. A motherboard‚ a CPU‚ a keyboard and a monitor are all items of hardware What is Software? Software is a collection of instructions that can be ‘run’ on a computer. These instructions tell the computer what to do. Software is not a physical thing (but it can of course be stored on a physical medium such as a CD-ROM)‚ it is just a bunch of codes. An operating
Premium Computer network Personal computer Computer
WJEC CBAC AS/A LEVEL GCE in Chemistry REVISION AID UNIT 1 AS UNIT CH1 – Controlling and Using Chemical Changes (in order to make things‚ produce energy and solve environmental problems) Preamble This unit begins with some important fundamental ideas about atoms and the use of the mole concept in calculations. Three key principles governing chemical change are then studied‚ viz. the position of equilibrium between reactants and products‚ the energy changes associated with a
Premium Atom
Development Structure of Atoms The structure of atoms developed throughout time since 410 BCE to now. “Leucippus of Miletus (ca. 435 BCE) and Democritus of Abdera (ca. 410 BCE) developed the atomic hypothesis.” Their Theory was that the world is made up of atoms moving around in empty space‚ also in continuous motion and constantly colliding into each other. The ancient Greek philosophers were the first people to have the theory of atoms and no one continued their theory until early 1803 which
Free Atom Electron
flows in an aqueous solution of ionic compounds‚ the metal ions appears at the negative electrode (cathode). - The metal exists in the solution as positively charged particles known as ions. - A 1+ ion plus one unit of electricity gives one metal atom. - Low pressures gases conduct electricity very well. - The glass of containing vessel opposite the cathode (negatives electrode) glowed when the applied potential difference (voltage) was sufficiently high. - Solid objects cast shadows between
Premium Atom Chemistry
Chemistry IGCSE Paper 6 revision guide You can change the temperature and concentration used (not both at the same time though) You need to keep the diameter of the conical flask the same‚ if it is thinner then the cross will disappear sooner‚ the cross also has to be the same‚ volumes too (This set up is mostly if you want to test the gases‚ otherwise you can use the standard set up) The limestone cycle: 1. Burn the limestone
Premium Sodium hydroxide Chlorine Carbon dioxide
made of one type of particle (atom). Particles can join up with other particles of the same type to form molecules. Examples: Hydrogen = H2 . This means there are two atoms of hydrogen joined together to form a molecule of hydrogen gas. Oxygen = O2‚ Nitrogen is H2‚ Chlorine is Cl2. A compound is a pure substance of two or more elements chemically combined together in a set ratio. Example: Water = H20 this means there are always 2 atoms of Hydrogen and 1 atom of Oxygen in every molecule of
Premium Chemical element Chemistry Carbon dioxide
Part I Multiple choice or short answer questions 1) (2 points) Identify a solid a. Definite volume and no definite shape b. no definite volume and no definite shape c. definite volume and definite shape 2) (2 points) A substance composed of two or more elements in a fixed‚ definite proportion is a. A solution. b. A heterogeneous mixture. c. An alloy. d. A homogeneous mixture. e. A compound. 3) (2 points) Read the water
Premium Atom Neutron Molecule
run-off through stormwater drains enters the Narrabeen Lagoon. Task 2: Mapping the School You need to measure an area of the school grounds. You have been given a map of the school. Choose an area of the school you wish to measure. Example‚ the Science block‚ tennis court etc. Go outside and measure distance. Compare to size on map to develop a scale. For example‚ the Pool is 25m long and is 2cm on the map. Therefore every 1cm on the map = 12.5m. You then need to record: • Total area of the
Premium Water
Faculty of Science Undergraduate Modular Scheme Session 2010/2011 Semester 1 Level 3 ------------------------------------------------- MODULE: SM0260: Chemistry for Life Sciences ------------------------------------------------- ------------------------------------------------- DATE: 17 January 2011 ------------------------------------------------- ------------------------------------------------- TIME: 14.00 – 16.00 Instructions to Candidates This paper contains
Premium Electron Electron configuration Atom
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education *8621469522* COMBINED SCIENCE CO-ORDINATED SCIENCES Paper 6 Alternative to Practical 0653/06 0654/06 May/June 2009 1 hour Candidates answer on the Question paper No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number‚ candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams‚ graphs
Premium Oxygen Hydrogen peroxide Sulfuric acid