Grade 8 Chemistry January - Feb

• What are metals?


  Elements that are good conductors of heat and electricity.
• What are Non metals?


  Elements that are poor conductors of heat and electricity.
• Properties of Non-Metals?


  Brittle, poor conductors of heat and electricity, non-lustrous
• What are metalloids?


  Elements that have properties of both metals and nonmetals.
• Example of mettalloids?


  Boron, Silicon
• Differences between Metals and Non-Metals?

  Metals are shiny while Non metals are not. Metals have a high melting point while non metals have a low melting point.
• What does the term Malleable mean?


  Can be beaten into thin sheets
• What does the term ductile mean?

  Can be drawn into thin wires
• What does sonourous mean?

  Produce a ringing sound when hit by something
• What does Lustorous mean?

  Can reflect light from their surface and can be polished
• What is the meaning of Brittle?

  Unable to stretch, easily broken
• What is the meaning of Conductors?

  Materials which allow electricity or heat to flow through them.
• Examples of Metals?


  Sodium and Magnesium
• What is a periodic table?

  A group of chemical elements, Organizes all discovered chemical elements in rows and coloumns according to increasing atomic number.
• What is a group?

  A group is a coloumn of elements in the periodic table
• Who formed the term "atomos"

  Democritus
• When did Democritus discover the atom?

  2500 years ago
• What did Democrtus believe in?

  He believed that all matter was made up of indivisble or uncutable atoms
• When did John dalton innovate the atom?

  1808
• What were john daltons beliefs?

  • He believed that matter CONSISTS of indivisble atoms, He believed that atoms were tiny spheres
• JJ Thompson?


  1904
• What was JJ thompson's model called?

  Plum pudding model
• What did JJ thompson discover?

  Electrons which were smaller than atoms
• Ernest Rutherford?


  1911
• what did Ernest Rutherford discover?

  The nucleus and the nuclear model
• Who discovered orbitals?


  Erwin shrodinger
• What model did Erwin shrodinger make?

  Quantum Mechanical Model
• What is an atom?

  It is the smallest particle of an element that can exist on its own
• What are the 2 regions of the atom?

  Nucleus and Shells\
• What is the nucleus?

  The central part of an atom that contains protons and neutrons, most of the mass of the atom is found here
• What are the shells?

  The outer region of the nucleus where the electrons are found
• The image below is a basic atom label it.

  A) Neutrons

  B) Protons

  C) shell

  D) nucleus

  E) Elecrtons