Atoms

• What is the smallest part of an element?

  Atom
• What is the approximate radius of an atom?


  About 0.1 nm (1x10^-10 m)
• What is the approximate radius of the nucleus of an atom?


  Less than 1/10000 (about 1x10^-14 m)
• How many different types of elements are approximately on the periodic table?


  About 100
• What is the relative charge of a proton?


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


  1
• What is the relative charge of a neutron?


  0
• What is the relative mass of a neutron?


  1
• What is the relative charge of an electron?


  • 1
• How does the relative mass of an electron compare to protons and neutrons?


  Very small
• What is the relationship between the number of electrons and protons in an atom?


  The number of electrons is equal to the number of protons in the nucleus
• What is the overall electrical charge of an atom?


  Atoms have no overall electrical charge
• How do atoms of different elements differ?


  Atoms of different elements have different numbers of protons
• What does the atomic number represent?


  The number of protons in an atom of an element
• What is the mass number of an atom?


  The sum of the protons and neutrons in an atom
• What are isotopes?


  Atoms of the same element that have different numbers of neutrons
• What is the relative atomic mass of an element?


  An average value that takes account of the abundance of the isotopes of the element