1. Chemistry The study of matter and its properties, characteristics, and behaviors.

2. Subatomic Atomic Molecular Organelle Cellular

3. Tissue Nervous Tissue Brain Nervous System Pronghorn Antelope Organ Organ System Organism

4. Population Herd of Pronghorns Hawk Water Earth’s surface Community Ecosystem Biosphere Pronghorns Hawk Grass Pronghorns Snake Bushes Soil Air Snake

5. Matter Matter- anything that occupies space and has mass. Three States of Matter Solid ~ Definite Volume, and Definite Shape Liquid ~ Definite Volume, No Definite Shape Gas ~ No Definite Volume and No Definite Shape

6. Element A substance that cannot be broken down into a simpler substance by ordinary chemical means.

7. Periodic Table Periodic Table of Elements ~ an arrangement of the elements according to the structure of their atoms. Element symbols ~ usually the first letter or letters of the names of the elements (Can be English, Latin, or Greek.) Examples ~ Oxygen: O, Carbon: C, Copper: Cu, from the Latin name, Cupurum.

9. Atom Atom ~ the smallest unit of an element that is still that element. An atom is composed of three types of particles:  Proton (p+): positively charged particle, located in the nucleus.  Neutron (n): neutral, or has no charge, also located in the nucleus.  Electron (e-): negatively charged particle, orbiting the nucleus.

10. Subatomic Particles Atoms of different elements differ in the number of subatomic particles (protons, neutrons, and electrons)  The atomic number is equal to the number of protons in an atom. If the atom is neutral then the number of protons and electrons will be the same.  Atomic mass is the mass of the atom (measured in atomic mass units)  Mass number is the same number as the atomic mass but it is the number of protons and neutrons (just a number)

11. Ions and Isotopes If you change the number of electrons, then you get an ion. If you change the number of neutrons, then you get an isotope. If you change the number of protons, then you get a new element.

13. Electrons and Bonding The arrangement of electrons in the shells, or orbits, is known as electron configuration. You must understand the electron configuration in order to fully understand bonding. Atoms are stable when their outer shell is full. Shell Maximum number of electrons 1 2 2 8 3 8,18 4 8,18,32 5 8,18,32

14. Figure 2.5 Hydrogen First shell Second shell Third shell Lithium Sodium Beryllium Magnesium Boron Aluminum Carbon Silicon Nitrogen Phosphorus Oxygen Sulfur Fluorine Chlorine Helium Neon Argon

15. Table 2.6

16. Chemical Bonding Two Main Types Ionic Bonding Covalent Bonding Most atoms are unstable and will bond with other atoms to be more stable. *An atom is considered stable when its outermost electron shell is full. *Atoms whose outer shell is not full are willing to give, get or share electrons to become stable, and are considered chemically active. In an atom the electron shells fill as follows: Innermost shell ~ can hold up to 2 e- Second shell ~ can hold up to 8 e- Third shell ~ can hold up to 18 e-, but is stable with 8 e-.

17. Compounds ~ a substance formed from 2 or more different elements in definite proportions. Molecule ~ the smallest unit of a compound that is still that compound in a natural state Molecular formula ~ expresses clearly the number and type of atom in a molecule or compound. Structural formula ~ shows where molecules bond to other molecules to form compounds.

18. Table 2.6

19. Ionic Bonding Ionic Bonding ~ the giving and taking of electrons or the transfer of electrons Ion ~ an atom with a positive or negative charge

20. Example of Ionic Bonding An atom of chlorine, Cl, a nonmetal, has 17 e-: 2 e- in the first shell 8 e- in the second shell 7 e- in the third shell If it gets one more electron, it will have a full outer shell. An atom of sodium, Na, a metal has 11 e-: 2 e- in the first shell 8 e- in the second shell 1 e- in the third shell If it gives away the outermost electron, it will have a full outer second shell. When these two meet ~ sodium gives its 1e- in the third shell to chlorine. This gives sodium a full outer shell (2 nd shell) and chlorine a full outer shell (3 rd shell).

21. Figure 2.7A_s2 Transfer of electron Na Sodium atom Cl Chlorine atom

22. Figure 2.7A_s2 Transfer of electron Na Sodium atom Cl Chlorine atom Na  Sodium ion Cl  Chloride ion Sodium chloride (NaCl)

23. Since one atom give an electron and one atom takes an electron, the atoms of chlorine and sodium have unequal numbers of electrons and protons. Sodium ~ positively charged ion, because it lost an e- Chlorine ~ negatively charged ion, because it gained an e- The positive and negative ion are attracted to each other and form sodium chloride.

24. Figure 2.7B Na  Cl 

25. Covalent Bonding The sharing of electrons. Electrons are shared between atoms. They are not transferred from one atom to another like in ionic bonding. Equal sharing of electrons = nonpolar covalent bond Unequal sharing of electrons = polar covalent bond Electronegativity- how much an atom wants an electron. An atom with a high electronegativity really wants an electron. Electronegativity generally increases up and to the right from Francium (Fr) to Fluorine (F). You can easily calculate the electronegativity difference of two atoms. That is what determines the type of bond that will form. Large difference = ionic Medium difference = polar covalent Little or no difference = nonpolar covalent

27. Example of Covalent Bonding Water is a great example of covalent bonding Hydrogen has only 1e- in its electron shell. Oxygen has 8 e- 2 e- in its first shell 6 e- in its second shell Oxygen needs two more electrons to complete the outer shell and the hydrogens each need one more. So, two hydrogen atoms will each share their one electron with an oxygen atom. Therefore, all the outer shells are full, and a covalent bond has formed.

28. Water Oxygen is much more elctronegative than hydrogen so the shared electrons spend more time next to the oxygen. There is an unequal sharing of electrons. Therefore, water is a polar molecule. The oxygen has a partial negative charge and the hydrogens have a partial positive charge.

29. Figure 2.6 (slightly  ) (slightly  ) (slightly  )

30. Figure 2.8 Hydrogen bond

31. Hydrogen Bonds Weak bonds important in the chemistry of life Hydrogen, as part of a polar covalent bond, has a partial positive charge. The charged regions on molecules are electrically attracted to oppositely charged regions on neighboring molecules. Because the positively charged region is always a hydrogen atom, the bond is called a hydrogen bond.

32. The fact that water molecules are held together by hydrogen bonds is extremely important. It leads to many different characteristics of water that help to sustain life on Earth.

33. The chemistry of life is sensitive to acidic and basic conditions In aqueous solutions, a small percentage of water molecules break apart into ions. –Some are hydrogen ions (H + ). –Some are hydroxide ions (OH – ). –Both types are very reactive. © 2012 Pearson Education, Inc.

34. The chemistry of life is sensitive to acidic and basic conditions A compound that releases H + to a solution is an acid. A compound that accepts H + is a base. The pH scale describes how acidic or basic a solution is. –The pH scale ranges from 0 to 14, with zero the most acidic and 14 the most basic. –Each pH unit represents a tenfold change in the concentration of H +. © 2012 Pearson Education, Inc.

35. The chemistry of life is sensitive to acidic and basic conditions A buffer is a substance that minimizes changes in pH. Buffers –accept H + when it is in excess and –donate H + when it is depleted. © 2012 Pearson Education, Inc.

36. Figure 2.14 Acidic solution Neutral solution Basic solution Oven cleaner Increasingly BASIC (Higher OH  concentration) Increasingly ACIDIC (Higher H  concentration) NEUTRAL [H  ]  [OH  ] Household bleach Household ammonia Milk of magnesia Rainwater Human urine Saliva Pure water Human blood, tears Seawater Tomato juice pH scale Battery acid Lemon juice, gastric juice Vinegar, cola

37. Figure 2.14_1 Increasingly ACIDIC (Higher H  concentration) Tomato juice pH scale Battery acid Lemon juice, gastric juice Vinegar, cola NEUTRAL [H  ]  [OH  ] Rainwater Human urine Saliva Pure water

38. Figure 2.14_2 Oven cleaner Increasingly BASIC (Higher OH  concentration) NEUTRAL [H  ]  [OH  ] Household bleach Household ammonia Milk of magnesia Pure water Human blood, tears Seawater pH scale

39. Figure 2.14_3 Acidic solution Neutral solution Basic solution