1.1.1 Elements

• What is an atom?

  An atom is the smallest part of an element that can exist.
• What is an element?

  An element is a substance of only one type of an atom.
• How are the elements listed and approximately how many are there?

  They are listed in the periodic table and are around 100 elements.
• Elements can be classified into two groups based on their properties; what are these groups?

  Metals and non-metals.
• Elements may combine through chemical reactions to form new products; what are these new substances called?

  Compounds.
• What is an isotope? Do isotopes of a certain element have the same chemical properties?

  Atoms of the same element (same proton number) that have a different number of neutrons. They have the same chemical properties as they have the same electronic structure.
• Compare the properties of metals and nob-metals.

  Metals: Boiling/melting point: High, Conductivity: Heat and electricity, Appearance: shiny, Malleability: Yes, Density: High, Oxides: basic. Non-Metals: Boiling/melting point: Low, Conductivity: Don't conduct heat electricity (exception of graphite), Appearance: Dull, Malleability: Brittle, Density: Low, Oxides: Acidic.
• The majority of elements are?

  Metals.
• Elements that react to form positive ions are?

  Metals.
• Elements that do not form positive ions are?

  Non-Metals.