2.1 BASIC CONCEPT OF MATTER

• What is matter?

  Something that has mass and occupies space. It consists of particles that are tiny and discrete. Matter can exist in three forms : liquid,gas,solid.
• When heat is energy absorbed or released, what changes occur?

  Changes occur in:

  • kinetic energy
  • arrangement of particles
  • attraction force between particles
  • state of matter
• MATTER EXIST IN THE FORM OF?

  Elements and compounds.
• ELEMENTS CONSIST OF?

  Particles of atoms or molecule.
• Compounds are made up of?

  Molecule or ions.
• All compounds are molecules, but not all molecules are compounds.
• How are ions formed?

  By transferring of electrons between atoms.

  
• What is meant by melting point?

  Melting point is the constant temperature when a substance changes from solid state to become liquid at a specific pressure.
• What is meant by freezing point?

  Freezing point is the constant temperature when a substance changes from liquid state to become solid at a specific pressure.