Chapter 2

• What is an element?


  An substance made up of only one type of atom
• What does the atomic number (Z) represent?

  The number of protons an element has
• What is an isotope?

  Atoms of the same element with different number of neutrons but with the same number of protons.

  • Therefore has a different mass
• How do isotopes react compared to their element?

  They react the same, number of neutrons doesn't affect chemical reaction characteristics and they have equal number of electrons.
• What are characteristics of the nucleus?

  Small and dense

  Contain almost all the mass

  Contain the positive charge
• What is the atom mostly made up of?

  Empty space
• What is an ion?


  A charged particle
• Define relative atomic mass?

  The weighted mean mass of an atom compared with 1/12th of the mass of an atom of carbon - 12.
• Define relative isotopic mass?

  The mass of an isotope compared with 1/12th of the mass of an atom of carbon-12.
• How can you determine the mass of an atom?

  Mass spectrometer:

  • heavier atoms move slower and take longer to reach the ion detector
• What are the charges of Zinc, Silver and Scandium?

  Zn 2+

  Ag +

  Sc 3+
• What is a polyatomic ion?

  Ion formed when groups of atoms from different elements lose or gain electrons.