Science - Chemistry

• The Atomic number tells us how many protons there are in an element
• Protons = Positive Charge
• Electrons = Negative Charge
• There are the same amount of electrons as protons in a neutral atom
• Atomic Mass = Protons + Neutrons
• On a periodic table the groups go down the page and they tell us the number of valence electrons ( outer shell )
• On a periodic table the period (across the page) tells us how many electron shells there are.
• Chemical/Valence bonds form between atoms when valence electrons are shared or exchanged