Chemistry - C1.1 - Fundamental Ideas

HideShow resource information

C1.1.1 - Atoms, Elements and Compounds

  • Everything is made from elements
  • Periodic table - list of elements, elements in same group have similar properties
  • Element - each made from different type of atom
  • Atoms - represented by chemical symbols, tiny nucleus surrounded by electrons, elements reacting - atoms join together = compound formed
1 of 5

C1.1.2 - Atomic Structure

  • Atom -> nucleus - centre of atom, contains protons (+) and neutrons (0), electrons (-) - move around nucleus, atom has no charge as no of protons = no of electrons and their charges are equal and opposite
  • Same element = same no of protons - atomic number = no of electrons, arranged according to atomic number in periodic table
  • Mass number = no of protons + no of neutrons (electrons have such a small mass that they aren't included)
2 of 5

C1.1.3 - The Arrangement of Electrons In Atoms

  • Electron = energy level - represented as shells - lowest energy level nearest the necleus
  • Lowest energy level (first shell) = 2 electrons, every other = 8 electrons
  • Elctrons occupy lowest possible energy level
  • Electronic structure - amount of electrons in each shell
  • Same group = same no of electrons in highest energy level
  • Group 1 - react quickly with H2O and O2
  • Group 0 - unreactive noble gases - stable arrangement of electrons
3 of 5

C1.1.4 - Forming Bonds

  • Elements combine to form compounds
  • Metal + non-metal = ions -> lose electrons = positive charge, gain electrons = negative charge, oppositely charged ions attract each other strongly - compound with iconic bonds
  • Chemical formula of ionic compounds tell us simplest ratio of ions
  • Non-metal + non-metal = covalent bonding and molecules form
  • Chemical formula of molecule tells us no of atoms in molecule, covalent bonds shown as lines when drawn
4 of 5

C1.1.5 - Chemical Equations

  • Reactions - atoms rearrange themselves to form the products, atoms aren't create or destroyed -> no of atoms before = no of atoms after, mass of products = mass of reactants
  • We write chemical equations to represent reactions -> word equations = names, symbols = numbers and types of atoms
  • Symbol equations need to be balanced, so no of each atom is the same on each side
  • Making equations balance - change large numbers in front of fomulae - NOT small numbers
5 of 5


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Atoms resources »