atoms and ions

• What are all things made up of?

  Lots of tiny particles called atoms
• How many atoms are in a single cell?

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

  A central nucleus surrounded by electrons
• 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 2,000 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 typical radius of an atom?

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

  The area between the nucleus and electrons
• How does the size of the nucleus compare to the atom?

  The nucleus is 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 elemental symbol represent?

  It represents a specific element
• What does the atomic number indicate?

  How many protons an atom has
• 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 if it has eight protons?

  Eight electrons
• How many electrons does an atom have if it has three protons?

  Three electrons
• What are the key components of an atom's structure?

  • Central nucleus
  • Protons and neutrons in the nucleus
  • Electrons orbiting in shells
• What are the charges and relative masses of protons, neutrons, and electrons?

  • Protons: +1 charge, relative mass of 1
  • Neutrons: 0 charge, relative mass of 1
  • Electrons: -1 charge, relative mass of 1/2000
• What is the relationship between atomic number and element identity?

  • Atomic number indicates the number of protons
  • Determines the identity of the element
• What information does the nuclear symbol provide?

  • Elemental symbol
  • Atomic number (number of protons)
  • Mass number (total of protons and neutrons)
• How do ions differ from neutral atoms?

  • Ions have unequal numbers of protons and electrons
  • Resulting in a net charge