WATER ATOMS GOLD ATOMS Let’s watch….. What is the diagram hanging in the front of the room? What does it show?

 A pure substance made of only one kind of atom.  Represented by symbols and organized on a Periodic Table of Elements. Let’s predict the elements shown.

CALLED PERIODS We read the periodic table from left to right. Increasing atomic mass from left to right. (the atoms get bigger) CALLED GROUPS OR FAMILIES They share the same reactivity and properties. (like brothers and sisters) Let’s check out how families are similar!

Alkali Metals Nobel Gases METALS NONMETALS Let’s predict! What elements are found in all living things (Including us)?

MATTER ATOMS PROTONSNEUTRONS ELECTRONS

 What are the three subatomic particles that atoms are made of? (Hint: Look at your notes if you need to)  We will be investigating the first 18 elements since they are the most common to biology. Protons Neutrons Electrons

 Let’s see what your previous knowledge is!  Working with a partner make a model of an atom using the clay at your desk.  Use the plate as the “nucleus”.  Protons = red (2)  Neutrons = purple (2)  Electrons = orange (2)

Orbital / Energy Level Electron (-) negative Nucleus: Protons (+) positive Neutrons (o) Neutral

The atomic number gives you the number of _____________of the element. This number equals the number of ____________. protons electrons Let’s practice! Gold has an atomic number of 79 – How many Protons and Electrons does it have? 79 protons 79 electrons Oxygen has an atomic number of 8 – How many Protons and Electrons does it have? 8 protons 8 electrons

To calculate the neutrons of an element Step 1: Round the mass number to the whole number Step 2: Subtract the atomic number from the mass number Let’s practice! Helium: Mass Number is: Atomic Number is: Chlorine: Mass Number is: Atomic Number is:

 Also called “orbitals” or “shells”.  Electrons are found in the orbitals.  Electrons go around the nucleus of the atom. 2 e- 8 e- 8 e-1 18 e- 18 e- P+ n 0

 The electrons in the last shell or energy level of an atom.  Determine the properties and chemical reactivity of the element and participate in chemical bonding.

 Let’s look at the first 18 elements on the periodic table. These are the elements most common to biology.  We will color code the subatomic particles and include the orbitals or energy level for each element.  Let’s do one together!

1. Draw nucleus, shade in & include # of p+ c 2. Draw in the energy levels & electrons (e-) a. 1 st Energy Level = Blue b. 2 nd Energy Level = Red c. 3 rd Energy Level = Green #p+ #n 0

Atomic # Name Symbol Nucleus Orbital

 Build an accurate model of any element you choose, from  Use a plate as the nucleus  Use red pom poms as protons  Use black pom poms as electrons  Be prepared to explain your model