Chemistry

• Elements are classified into metals (on the left side) and non-metals (on the right side).
• The periodic table is arranged by increasing atomic number, with elements having similar properties grouped together.
• element


  substance that CANNOT be chemically broken down into simpler substances

  
• atom


  smallest part of an element that can be identified as that element

  
• nucleus


  center, or core, of an atom (where the protons and neutrons are located)

  
• proton


  particle that has a positive charge - located in the nucleus of an atom. You can figure out the number of protons by looking at the atomic number of an element.

  
• neutron


  particle that has no charge - located in the nucleus of an atom. You can figure out the number of neutrons by SUBTRACTING the atomic Mass minus the atomic number.

  
• electron


  particle that has a negative charge - located in rings outside the nucleus of an atom. You can figure out the number of electrons by looking at the atomic number of an element.

  
• atomic number


  number of protons in the nucleus of an atom. This is the same number as the number of electrons

  
• atomic mass


  total mass of the protons and neutrons in an atom

  
• metal


  element that has the property of shiny luster, ductility, and malleability

  
• malleable


  able to be hammered into different shapes

  
• ductile


  able to be drawn into thin wires

  
• nonmetal


  element that lacks most of the properties of a metal, is not shiny, does not conduct electricity or heat well, is not malleable so it is called brittle or breakable.

  
• halogens


  elements that make up Group 17 in the periodic table

  
• noble gases


  elements that make up Group 18 in the periodic table

  
• properties


  characteristics used to describe an object

  
• solid


  state of matter with a definite shape and volume

  
• liquid


  state of matter with a definite volume but no definite shape

  
• gas


  state of matter that has no definite shape or volume

  
• chemical formula


  way of writing the name of a compound using chemical symbols

  
• chemical equation


  statement in which chemical formulas are used to describe a chemical reaction

  
• chemical reaction


  process in which new substances with new chemical and physical properties are formed

  
• reactant


  substance that is changed in a chemical reaction

  
• product


  substance that is formed in a chemical reaction

  
• molecule


  smallest part of a substance that has all the properties of that substance - more than one element, like hydrogen and oxygen make water

  
• chemical bond


  force of attraction that holds atoms together

  
• covalent bond:

  formed between 2 non metals to form a chemical bond by sharing electrons
• diatomic molecules:

  two atoms that are bonded together
• delocalised:

  ions are free to move
• pure substance:

  a single element or compound not mixed with any other substance
• melting point:

  a temperature which a solid changes into a liquid (the same temperature as the freezing point, 0°)
• boiling point:

  the temperature at which a liquid changes into a gas
• formulation:

  a mixture that’s been designed as a useful product. it’s formed by mixing together several different substances in carefully measured quantities to ensure the product has the required properties
• alloy:

  a mixture with two or more elements, at least one is metal. eg: gold, silver, copper)
• soluble:

  dissolves in water
• insoluble:

  doesn’t dissolve in water
• solute:

  the solid that dissolves
• solvent:

  the liquid in which the solute dissolved (eg: water)
• solution:

  resulting mixture of solute dissolving in a solvent