Atoms and Ions #1

• What are all things made up of, including living organisms?

  Atoms
• How many atoms are estimated to be in a single cell?

  More than 100 trillion
• What is the basic structure of an atom?

  • Central nucleus
  • Electrons orbiting in shells
• What particles make up the nucleus of an atom?

  Protons and neutrons
• What is the relative mass of protons and neutrons?

  Both have a relative mass of one
• How does the mass of electrons compare to protons and neutrons?

  Electrons are about 2000 times smaller
• What is the charge of protons?

  Protons have a positive charge of +1
• What charge do neutrons have?

  Neutrons have no charge and are neutral
• What is the charge of electrons?

  Electrons have a negative charge of -1
• How can you remember the charges of protons, neutrons, and electrons?

  • Protons are positive (both start with 'p')
  • Neutrons are neutral (both start with 'n')
  • Electrons are negative (the only one left)
• What is the approximate radius of an atom?

  About 0.1 nanometers
• What is mostly found in an atom?

  Empty space
• How does the size of the nucleus compare to the size of the atom?

  The nucleus is 10,000 times smaller than the atom
• How many protons and electrons are in the drawn atom example?

  Three protons and three electrons
• What happens when an atom gains or loses electrons?

  It becomes an ion
• What is a negative ion?


  An atom with more electrons than protons
• How is a one minus negative ion formed?

  By adding one extra electron to an atom
• What is a positive ion?


  An atom with more protons than electrons
• How is a one plus positive ion formed?

  By losing one electron from an atom
• What does the periodic table represent?

  • Different types of atoms called elements
  • Each box represents a different element
• What does the elemental symbol represent?


  It represents the element
• What is the atomic number?

  It tells us how many protons an atom has
• Why is the atomic number important?

  It determines which element an atom is
• How do you find the number of neutrons in an atom?

  Mass number minus atomic number
• How many neutrons does oxygen have if its mass number is 16 and atomic number is 8?

  8 neutrons
• How many neutrons does lithium have if its mass number is 7 and atomic number is 3?

  4 neutrons
• How many electrons does an atom have based on its atomic number?

  It has the same number of electrons as protons
• How many electrons does oxygen have if its atomic number is 8?

  8 electrons
• How many electrons does lithium have if its atomic number is 3?

  3 electrons