Why are chemical equations balanced? Write an example of balanced chemical equation.

C3H8+O2–>H2O+CO2

They need to be balanced so they can follow the low of conversation of mass

Use your periodic table to  determine  whether an  element  is a metal or a non-metal and how many valence electrons it has to   determine if  it  will bond  by transferring (ionic/electrovalent) or sharing (covalent) valence electrons. in general,compounds  formed between a metal and a non-metal  will  contain  ionic  bonds.