Atoms

• What is an atom?

  The smallest part of an element that can still be recognised as that element.
• What is charge ?

  A property of particles that is positive, negative or neutral.
• What happens when like charges come into contact?

  They repel
• What happens when opposite charges come into contact?

  They attract
• Which particles are found in the atoms nucleus?

  protons and neutrons
• What are the 3 subatomic particles?

  Protons, neutrons and electrons
• Where are the electrons found in atoms?

  Orbiting the nucleus, on the shells
• What are the masses of the subatomic particles?

  Proton : 1

  Electron : 1

  Neutron : 0
• What are the relative charges of the subatomic particles?

  Proton : +1

  Electron : -1

  Neutron : 0
• What is the atomic number of an atom?

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

  The number of protons + neutrons
• Why is the number of electrons in an atom equal to the number of protons?

  Protons are positive and electrons are negative so the charges cancel out.
• How do you calculate the number of neutrons in an atom?

  Mass number - Atomic number
• What is the typical size of an atom?

  They have a radius of approximately 0.1 nm.
• How large is the nucleus of an atom relative to it's radius?

  Approximately 1/10000th the size
• What is a molecule?

  Two or more atoms joined by a covalent bond