Ch 3 Atomic Structure

• What is an atom?


  smallest particle that can still have chemical characteristics of an element
• What makes atoms behave so differently?

  different types of atoms contain different number of sub-atomic particles
• What are protons?


  -Found in the nucleus

  -carry positive electrical charge

  -relative mass of 1
• What are neutrons?


  -Found in the nucleus

  -neutral - no net electrical charge

  -relative mass of 1
• What are electrons?


  -Found in the electron shell

  -carry negative electrical charge

  -relative mass of 1/1840 (negligible)
• Why are atoms electrically neutral?


  -number of protons is equal to the number of electrons

  -electrical charge is balanced off
• What is proton number (Z)? (atomic number)


  number of protons in the nucleus
• What is the nucleon number (A)? (mass number / relative atomic mass number)


  total number of protons and neutrons in the nucleus
• How do you find the number of neutons?


  Nucleon number - proton number
• How do you write nuclide notation of carbon?

  nucleon number above and in front of atomic symbol of element, proton number below and in front of atomic symbol of element