elements

• How many naturally occurring elements are there?

  92
• What defines an element?

  A substance made of one type of atom
• What is gold made of?

  Gold atoms
• What is the periodic table used for?

  To learn about elements and their properties
• Which elements are suggested to learn first?

  The first 20 elements
• What are the first 5 elements in the periodic table?

  • Hydrogen
  • Helium
  • Lithium
  • Beryllium
  • Boron
• How do elements form compounds?

  Through chemical reactions, not mixtures
• What are the two types of compounds?

  • Covalent
  • Ionic
• What is an ion?

  An atom or molecule with a charge
• What happens when an atom gains or loses electrons?

  It becomes an ion
• What are examples of positive ions?

  Na⁺, Mg²⁺, Ca²⁺
• What are examples of negative ions?

  Cl^-, F^-
• What charge do metal ions typically have?

  Positive
• What charge do non-metal ions typically have?

  Negative
• What are some common polyatomic ions?

  • Nitrate (NO₃^-)
  • Hydroxide (OH^-)
  • Carbonate (CO₃^2-)
  • Sulfate (SO₄^2-)
• What is the importance of balancing chemical equations?

  To have the same number of atoms on both sides
• What is the balanced equation for methane and oxygen?

  CH₄ + 2O₂ → CO₂ + 2H₂O
• How can you practice balancing chemical equations?

  By doing exercises and watching tutorial videos
• Who developed the periodic table?

  • Dmitri Mendeleev
• What resources can help with balancing equations?

  YouTube videos and practice exercises