lesson 1 - 2

• Non-metals are brittle and cannot be hammered or rolled into thin sheets.
• Atoms

  The smallest unit of matter that retains the properties of an element
• Neutrons

  A neutral particle found in the nucleus of an atom
• Solid

  A state of matter characterized by a stable shape and volume
• Chemical properties

  Properties that describe a substance's ability to undergo a chemical change or react with other substances
• Extensive properties

  A property of matter that depends on the amount of the sample
• Particles

  The smallest unit of an element or compound
• Irreversible physical change

  A physical change in which something changes in a way that does not alter its chemical makeup but can't be undone
• Matter

  Anything that has mass and volume
• Gas

  A state of matter characterized by no stable shape or volume
• Electron cloud

  The region around the nucleus of an atom where electrons are most likely to be found
• Electrons

  A negatively charged particle found in the electron cloud of an atom
• Intensive properties

  A property of matter that does not depend on the amount of the sample
• Physical properties

  Properties that can be observed or measured without changing the chemical identity of a substance
• Reversible physical change

  A physical change in which the original substances can be recovered back
• Protons

  A positively charged particle found in the nucleus of an atom
• Nucleus

  The central part of an atom, made up of protons and neutrons
• Ions

  An atom or molecule with a net charge due to the loss or gain of electrons
• Liquid

  A state of matter characterized by a stable volume but no stable shape
• Physical change

  A change to a sample of matter in which some properties of the material change, but not the chemical makeup
• Chemical change

  A change of materials into another, new materials with different properties and one or more new substances are formed