Atomic structure

• Atomic Structure

  • Atoms are the building blocks of all matter
  • Atoms have a tiny, dense, positively charged nucleus at their centre, with negatively charged electrons orbiting around the nucleus
  • The radius of the nucleus is over 10,000 times smaller than the whole atom, but it contains almost all of the mass of the atom
• ATOMIC STRUCTURE:

  A) Electron

  B) Proton

  C) Neutron

  
• Parts of the Atom

  • The nucleus contains:
  • Protons - positively charged particles with a relative atomic mass of one unit
  • Neutrons – no charge, and also with a relative atomic mass of one unit
  • Almost all of the atom is empty space, but moving around the nucleus there are:
  • Electrons – negative charge with almost no mass (1/2000 the mass of a proton or neutron)
• Size of Atoms & Molecules

  • Atoms are incredibly small, with a radius of only 1 × 10-10 m
  • This is 0.0000000001 m when written without standard form
  • This means that about one hundred million atoms could fit side by side across your thumbnail
  • A group of atoms can bond together to make molecules, such as water
  • A water molecule is comprised of two hydrogen atoms and one oxygen atom