Warm up Pg. 14 What is the smallest part of a living thing ? What is the smallest part of matter? Assignments: Chemistry Review (page ______)

Chemistry in Biology

Overview Review the parts of an Atom Review charges Review how to read the periodic table Review reactions and types of bonds Exit Ticket

Why study Chemistry in Biology? Digestion Photosynthesis Respiration These are all performed by interaction of molecules

And these are the elements you eat!! (mostly) Periodic Table Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus are the 4 elements all living organisms are made of! And these are the elements you eat!! (mostly)

Atom An atom is the smallest building block of matter. It is the smallest part of an element. Atom

Name the parts of an atom… Nucleus Protons Neutrons Electrons + + + + + +

Positively charged particles # of Protons = Atomic Number

Electrons Negatively charged particle. # of Electrons = # of Protons Electrons are located outside of the nucleus on energy levels in an area called the electron cloud.

No charge or neutral # of Neutrons = Mass Number – Atomic Number

Why do elements interact or react? Most atoms are not stable in their natural state Tend to react (combine) with other atoms in order to become more stable (undergo chemical reactions) In chemical reactions bonds are broken; atoms rearranged and new chemical bonds are formed that store energy

The Octet Rule Ionic: Covalent: Each type of bond requires that both atoms involved in the reaction fulfill an octet, or have 8 valence electrons. Ionic: One element donates its valence electrons (the metal), the other accepts the electrons (the nonmetal). Both fulfill the octet rule by donating/accepting valence electrons. Covalent: Both elements share their valence electrons to fulfill the octet rule. Both elements are nonmetals.

Na Cl Ionic Bonding Let’s see how sodium (Na) bonds with chlorine (Cl) Chlorine now has an octet (8 valence electrons) and sodium does too Na Metal Cl Nonmetal After donating/ accepting electrons, these atoms are now bonded together + New Compound

Covalent Bonding Let’s see how fluorine (F) bonds with itself Each fluorine atom has 7 valence electrons. They EACH need one more valence electron to fulfill the octet rule, so they will each SHARE one electron with each other. These are the shared electrons F Nonmetal + After sharing, these atoms are now bonded together

Lastly Hydrogen Bonds Oxygen Hydrogen Bond A hydrogen bond is the electromagnetic attraction between polar (positive and negative) molecules in which hydrogen is bound to a larger atom, such as oxygen or nitrogen. A hydrogen bond is the WEAKEST of the three bonds, they are easily broken and reattached Oxygen Hydrogen Bond

Exit Quiz What is the smallest building block of matter? Name the three subatomic particles in an atom. What is the positively charged particle called? What is the negatively charged particle called? What is the particle called that has no charge? What two subatomic particles make up the nucleus?

10/16/15 How many electrons can the first energy level hold? What element on the periodic table has that number of electrons to fill the first orbital? Assignments: Episode 6: The Atom V.G. Dalton and Thompson Worksheets (page 65)

10/19/15 Quarter 2 Week 2 What did Thompson add to the Ideas behind Dalton’s Atomic Theory of Matter? Assignment: Rutherford and Bohr Worksheets (page 65) Stamps: Dalton and Thompson

10/15/15 Where does the mass of the atom come from? Assignments: Atoms Family (Page 63) Episode 6: The atom Video Guide (page 64) Stamps: Exit Quiz