Atomic structure

• Atomic Number

  Number of protons in an atom

  
• Atomic Mass

  total weight of protons and neutrons

  
• atom

  smallest unit of matter

  
• nucleus of atom

  the positively charged dense center of an atom

  
• neutron


  A subatomic particle that has no charge and that is found in the nucleus of an atom

  
• proton

  A subatomic particle that has a positive charge and that is found in the nucleus of an atom

  
• electron

  A subatomic particle that has a negative charge

  
• Periodic Table

  A chart of the elements showing the repeating pattern of their properties

  
• What is the subatomic particle a?

  Electron

  
• What is the subatomic particle b?

  Neutron

  
• What is the subatomic particle c?

  Proton

  
• atom

  Smallest particle of an element

  
• proton

  A subatomic particle that has a positive charge and that is found in the nucleus of an atom

  
• neutron


  A subatomic particle that has no charge and that is found in the nucleus of an atom

  
• electron

  A subatomic particle that has a negative charge

  
• electron cloud


  the area around the nucleus of an atom
• atomic number

  the number of protons in the nucleus of an atom

  
• mass number


  the sum of the number of neutrons and protons in an atomic nucleus

  
• atomic mass unit

  a unit of mass that describes the mass of an atom or molecule

  
• Family or group of elements

  a column of elements in a periodic table

  
• property

  Characteristic used to describe something
• chemical change

  A change in matter that produces one or more new substances

  
• physical change

  A change in a substance that does not involve a change in the identity of the substance

  
• pure substance

  A sample of matter, either a single element or a single compound, that has definite chemical and physical properties