3. Matter – anything that takes up space and has mass; composed of elements Elements – composed of chemically identical atoms bulk elements – required by the body in large amounts trace elements – required by the body in small amounts Atoms – smallest particle of an element that still behaves like the element

4. Molecules – particle formed when two or more atoms chemically combine Compound – particle formed when two or more atoms of different elements chemically combine Molecular formulas – depict the elements present and the number of each atom present in the molecule H 2 C 6 H 12 O 6 H 2 O 2-7

5.  Example CaCO 3  1 calcium atom (one understood)  1 carbon atom (one understood)  3 oxygen atoms (3 subscript)

6. Structural formulas show how atoms bond and are arranged in various molecules

7.  SPONCH- Are the main elements of life 97% of the elements in living things  Sulfer  Phosphorus  Oxygen  Nitrogen  Carbon  Hydrogen

8. 20 elements that are found in small amounts Play important roles in the body’s processes I, Zn, Cu, B, Mn, F, Mg, Na, Ca, K,Fe.

11.  Contains the mass of the atom ˙ Protons (p + ) which are positive particles ˙ 1 proton = 1 AMU (Atomic Mass Unit) ˙ Neutrons (n o ) which are neutral particles ˙ 1 neutron = 1 AMU

12.  Electrons (e - ) which are negative particles orbit outside of the nucleus - electrons have so little mass that it isn’t measured

13.  Atomic Number – Represents the # of protons in an element  Determines the element and its properties  #protons + = #electrons - What is overall charge on an atom?

14.  Sum of all protons & neutrons in an atom’s nucleus Example – Sodium (Na) mass number = 23 atomic number = 11. How many protons? How many neutrons? How many electrons?

15.  atoms of an element w/the same # of p+ but a different # of n o.  It changes the atomic mass  C 12 = 6 p +, 6 n 0, 6 e - 12 AMU  C 13 = 6 p +, 7 n 0, 6 e - 13 AMU  C 14 =? _?_ AMU

16.  Some isotopes are unstable and decay over time  Breakdown and release radioactive particles and energy as radiation to become stable form of another element Ex = C 14 becomes N 14  Biological uses of Radioactive Isotopes - carbon dating – find the age of bio material - molecular tracers – used to trace reactions in living things - nuclear medicine – imaging and cancer treatment

17.  Charged Atom – Atoms can gain or lose electrons to become charged  Anion - an element which gains electrons giving it more electrons than protons anions have a ________?__________charge  Cation - an element loses electrons, giving it more protons than electrons cations have a __________?________ charge

18.  Electrons that are found on the outer most orbital.  An atom can have  2e- first orbital  8 e- second orbital  18 e- third orbital  The octet rule - Atoms are most stable with 8 valence electron

19.  The Octet Rule - Atoms are most stable with 8 valence electrons - To become stable, atoms can:  give away electrons to other atoms  accept electrons from other atoms  share electrons with other atoms

20.  Chlorine has 17 electrons  2 in the first orbital  8 in the second orbital  7 in the third orbital  How many valence electrons does it have?  How many more does it need to be stable?  Should it gain or lose electrons?  What is its ionic charge?

21.  Sodium has 11 e-  2 e- in the first orbital  8 e- in the second orbital  1 e- in the third orbital  How many valence electrons does it have?  How many valence electrons does it need?  Is it easier to gain 7 or lose 1?  What is sodium’s ionic charge?

22.  Atoms with 1,2 or 3 valence electrons usually give away electrons and become positive ions (cations)  Atoms with 4 valence electrons can either give away or gain electrons  Atoms with 5,6, or 7 valence electrons usually gain electrons and become negative ions (anions)

23.  Atom, Nucleus, Proton, Neutron,Electron  Atomic Number  Mass Number  Isotopes, Ions, Cations, Anions  Valence Electrons

25.  Occur when atoms share e -  Nonmetal + nonmetal  Strong bonds  atoms can share up to 3 pairs of electrons  Two types - nonpolar covalent bond: atoms share e - evenly - polar covalent bond: atoms share e - unevenly

26.  One atom holds electrons longer - atom has a slight neg. charge  Other atom holds electrons less - atom has a slight pos. charge  Creates a molecule with charged poles  Water is a polar covalent molecule - gives water its important properties

27.  A weak attraction between polar molecules  Positive pole of one molecule is attracted to the negative pole of another Found between H 2 O Join DNA strands help give proteins molecules their shape

28.  Composed of ions (charged atoms) - remember ions give away or accept electrons to get a complete valence shell  Occur between metals and non metals  Metal donates electron(pos charge) + nonmetal accepts electron (- charge) = zero charge  Opposite charges attract – atoms join and create a new compound

30.  How do you bond potassium and oxygen  First determine their charges  K +1 O –2  Then criss cross the number (not the sign) and the number becomes the subscript.

31.  K+1 O-2  The final answer is K 2 O (the one is understood behind O)

32. Chemical Reactions  Atoms either join with another atom or switch partners  The making or breaking of bonds involves changes in energy - in living things, these energy changes can be stored, used to do work or released  Law of Conservation of Matter - during chemical reactions matter is neither created or destroyed

33. Balanced Equations  Chemical Equation – represents the chemical reaction Fe 2 O 3 + 3H 2 2Fe + 3H 2 O Reactants Products  According to the Law of Conservation of Matter, the equation must be balanced - the number of atoms of each element must be equal on each side of the equation

34. How many elements can carbon bond with? How many electrons does carbon have? How many valence electrons does carbon have? How many MORE electrons does carbon need to have a full outer orbital?

35.  Atom, Nucleus, Proton, Neutron  Atomic Number  Mass Number  Isotopes, Ions, Cations, Anions  Valence Electrons  Covalent Bond  Single, Double, Triple  Polar, Nonpolar

36.  Atom, Nucleus, Proton, Neutron, Electron,  Atomic Number  Mass NumberIsotopes, Ions, Cations, Anions  Valence Electrons  Covalent Bond,Single, Double, Triple, Polar, Nonpolar

37. Bond Bond Energy ( KCAL/MOL ) Relative Strength Covalent Bond 50 -100 KCAL/MOL Strong Hydrogen Bond 3-7 KCAL/MOL Weak – easily broken Ionic Bond 3-7 KCAL/MOL Weak – dissociates in H 2 O