Atoms, Elements and Compounds

• State the relative masses and relative charges of the Protons, Neutrons and Electrons

  • Protons -> Relative Mass: 1 / Charge: +1
  • Neutron -> Relative Mass: 1 / Charge: 0
  • Electrons -> Relative Mass: 0 / Charge: -1
• Explain why atoms are electrically neutral?

  • The have the same number of electrons AND protons
• What is the radius of an atom?

  • 0.1 nm
• What is the radius of a nucleus?

  • $1\times10^{-14}$
• What is the Atomic Number?

  • The number of PROTONS in a nucleus
• Where is the majority of the mass of an atom?

  • The nucleus
• What is the mass number?

  • The total number of PROTONS and NEUTRONS
• How do we calculate the number of NEUTRONS using the Mass Number and the Atomic Number?

  • Mass Number - Atomic Number
• What are isotopes?

  • An element which has the same number of PROTONS but, different number of NEUTRONS
• What are Mixtures?

  • Mixtures are substances that are made up of elements and compounds that AREN'T chemically bonded
• What are Compounds?

  • Compounds are substances that are made up of two or more elements chemically bonded
• State the equation for RAM

  • Isotope Abundance x Isotope Mass Number / 100