Atoms and ions

• What are all things made up of?

  Lots of tiny particles called atoms
• How many atoms does a single cell contain?

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

  A central nucleus surrounded by electrons
• What are the two types of particles in the nucleus?

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

  Both have a relative mass of one
• How much smaller are electrons compared to protons and neutrons?

  Two thousand times smaller
• What charge do protons have?

  Positive charge of one plus
• What charge do neutrons have?

  No charge, they are neutral
• What charge do electrons have?

  Negative charge of one minus
• How can you remember the charges of protons, neutrons, and electrons?

  Protons are positive, neutrons are neutral
• What is the radius of an atom?

  Around 0.1 nanometers
• What is mostly empty space in an atom?

  The area between the nucleus and electrons
• How much smaller is the nucleus compared to the atom?

  10,000 times smaller
• 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 do you denote a one minus negative ion?

  By having one extra electron
• What is a positive ion?

  An atom with more protons than electrons
• What does the periodic table represent?

  Different types of atoms called elements
• What does the atomic number indicate?

  How many protons an atom has
• How many protons does oxygen have?

  Eight protons
• How many protons does lithium have?

  Three protons
• 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?

  Eight neutrons
• How many neutrons does lithium have if its mass number is 7?

  Four neutrons
• How many electrons does an atom have?

  Same as the number of protons
• How many electrons does oxygen have?

  Eight electrons
• How many electrons does lithium have?

  Three electrons