C1 Atomic Structure

• What is the relative charge of a proton?

  +1
• What is the relative mass of a neutron?

  1
• What does the atomic number represent?

  Number of protons in an atom
• What is the relative charge of an electron?

  −1
• Why do atoms have no overall charge?

  Equal numbers of protons and electrons
• What are elements and compounds?

  • Elements: Substances made of one type of atom
  • Compounds: Different types of atoms chemically bonded
• What is a mixture?

  Two or more substances not chemically combined
• How can mixtures be separated?

  Using physical processes, not chemical reactions
• What are the methods to separate mixtures?

  • Filtration
  • Crystallisation
  • Simple distillation
  • Fractional distillation
  • Paper chromatography
• What are isotopes?

  Atoms of the same element with different neutrons
• How is relative atomic mass calculated?

  Average mass of all isotopes of an element
• What is the definition of relative atomic mass?

  • Average mass of all atoms of an element
• How many electrons can fit in the first shell?

  Up to two electrons
• How many electrons can fit in the second and third shells?

  Eight electrons each
• What did Dalton's model propose about atoms?

  Atoms are solid spheres that cannot be divided
• What is the nuclear model of the atom?

  Dense nucleus with electrons orbiting it
• What did Niels Bohr discover about electrons?

  Electrons orbit in fixed energy levels
• What did James Chadwick discover?

  Uncharged particle called the neutron
• Where are protons and neutrons located?

  In the nucleus
• What is the relative mass of a proton?

  1
• What is the relative mass of an electron?

  0 (very small)
• How can you find the number of protons in an atom?

  By looking at the atomic number
• How can you calculate the number of neutrons in an atom?

  Mass number minus atomic number
• What is the significance of the alpha scattering experiment?

  Showed mass and charge concentrated in nucleus
• What is the plum pudding model of the atom?

  Sphere of positive charge with electrons embedded
• What is the smallest part of an element that can exist?

  An atom
• What is a compound?

  Substance made of more than one type of atom
• What is an element?

  Substance made of one type of atom
• What is a mixture?

  Two or more substances not chemically combined
• What are isotopes?

  Atoms of the same element with different neutrons
• What are the four physical processes to separate mixtures?

  Filtration, crystallisation, distillation, chromatography
• What is relative mass?

  Average mass of all atoms of an element