Chemistry I Subatomic particles Electron configurations Carbon molecules Jill Hansen

1. Biology Partnership (A Teacher Quality Grant) Chemistry I Subatomic particles Electron configurations Carbon molecules Jill Hansen Tammy Stundon

2. Welcome! Pre-test Q and A Board

3. Florida Next Generation Sunshine State Standards ( SC.912.P.8.12): • 1. Describe the properties of the carbon atom that make the diversity of carbon compounds possible. • NOTE: While this unit is relatively light on actual standards, most of the material covered on the EOC requires a comprehensive understanding of chemical basics. • This lesson is designed for those who didn’t get it the first time!

4. DHMO

5. THE TOP 10 ELEMENTS FOUND IN YOUR BODY Why learn chemistry? THE “BIG 4” 96% of your body is composed of these 4 elements: Oxygen (65%) Percentage (%) of body’s composition • Chemical basics are at the root of every biological function • Neural impulse (Na/K pump) • Muscular contraction (Ca ion uptake) Carbon (18.5%) Hydrogen (9.5%) Nitrogen (3%) OTHER (4%) Calcium Sulfur Phosphorus Sodium Potassium Chlorine • Trace amounts (less than 0.1%) of 15 other elements are also found in the body

6. Atomic Structure • The universe is made up of matter • Matter is made up of atoms • Anything that takes up space and has weight • The smallest piece of gold possible is called an atom. If you divided it into smaller pieces, it would no longer be gold. Imagine dividing a gold ring in half, forever Atom = uncuttable An atom is the smallest basic unit of matter. An element is one type of atom.

7. Carbon Gold Each of the elements is however made up of 3 fundamental particles Copper AN ELEMENT IS A SUBSTANCE THAT CANNOT BE BROKEN DOWN CHEMICALLY INTO ANY OTHER SUBSTANCE

8. Oxygen atom (O) outermost energy level: 6 electrons (-) Nucleus:8 protons (+)8 neutrons inner energy level: 2 electrons (-) Atomic Structure All atoms have 3 fundamental particles • The nucleus has protons and neutrons. • Electronsare in energy levels outside nucleus.

9. THE ATOM: BASIC STRUCTURE Nucleus Hydrogen atom 1 Proton 0 Neutrons 1 Electron Carbon atom 6 Protons 6 Neutrons 6 Electrons Forces of attraction between positive and negative charges hold the fast-moving electrons (negative) close to the nucleus (positive). Nucleus: Proton Neutron Electron

10. Atomic Structure So how do you know if you have an atom of copper, gold or silver? How many protons an atom has determines who it is Cu = 39 Ag = 47 Au = 79 Atomic number is the number of protons Cookium diagnostic A KEY TO THE ELEMENTS ATOMIC NUMBER The number of protons found in the atom’s nucleus ELEMENT SYMBOL Abbreviation of the element ELEMENT NAME ATOMIC MASS Combined mass of the atom’s protons and neutrons

12. Atomic Structure So how do you know how many electrons and neutrons there are? A neutral atom will have equal numbers of protons and electrons P+ = E- The number of neutrons can be determined by subtracting the atomic number from the atomic mass P+N (atomic mass) – P (atomic #) = N Atomic Basics Worksheet

13. Atomic Structure Atoms are most stable if they have a filled (or empty) outer layer of electrons Where are the electrons found? Except for H and He, a filled layer contains 8 electrons – an octet Atoms will gain, lose, or share electrons to make a full or completely empty outer layer

14. ELECTRON SHELLS AND ATOM STABILITY ELECTRON SHELLS Electrons move around the nucleus in designated areas called electron shells. An atom can have as many as sevenelectron shells in total. First electron shell (capacity: 2 electrons) Second electron shell (capacity: 8 electrons) Vacancy The chemical characteristics of an atom depend upon the number of electrons in its outermost shell. An atom’s electrons determine whether an atom will bond with another atom as well as who it will bond with

15. Chemical Changes When atoms exchange or share electrons, a new product (a compound or molecule) is produced. This is called a chemical change. In a chemical change: • reacting substances form new substances with different compositions and properties. • a chemical reaction takes place. Chemical Change Lab

16. After the Lab: Balloon Buddy Your challenge: get the balloon to kiss you Simulation Ions (charged atoms) follow the rule that opposites attract Static electricity is a reflection of the difference in charges between objects

17. ELECTRON SHELLS AND ATOM STABILITY ATOM STABILITY Atoms become stable when their outermost shell is filled to capacity. Stable atoms tend not to react or combine with other atoms. Unstable atoms Stable atoms Hydrogen atom Helium atom Nitrogen atom Neon atom Only when atoms have electron vacancies in their outermost shell are they likely to interact with other atoms.

18. gained electron Na loses anelectron to CI ionic bond Sodium ion (Na+) Chlorine atom (CI) Sodium atom (Na) Chloride ion (CI-) Ions form when atoms gain or lose electrons • An ion is an atom that has gained or lost one or more electrons. • positive ions (cation) • negative ions (anion) • Ionic bonds form between oppositely charged ions.

19. IONS ARE CHARGED ATOMS An atom that loses one or more electrons becomes positively charged, while an atom that acquires electrons becomes negatively charged. This transfer of electrons is driven by the fact that atoms with full outer electron shells are more stable. Donated electron Na Cl Sodium ion Chloride ion 11 Protons 10 Electrons 17 Protons 18 Electrons NET CHARGE Positive Negative

20. Ionic Bonds Formed between ions OPPOSITE CHARGES ATTRACT

21. COVALENT BONDS 1 Hydrogen atoms are most stable when their outer electron shell is filled to capacity. They can achieve this by sharing electrons in a covalent bond. Hydrogen atom Hydrogen atom 2 The nuclei come closer together and the two electrons begin to circle around both of them. The new H2 molecule is very stable. H2 molecule Covalent bonds form electrically neutral molecules. Covalent bond are very strong bonds, common in most organic molecules

22. Covalent Bonds A molecule is made of atoms sharing electrons • water (H2O) • carbon dioxide (CO2)

23. Covalent Bonds Molecule A chemical structure held together by covalent bonds The chemical structure shows the number of each element forming the molecule (CH4)

24. SUMMARY: THREE TYPES OF BONDS 1COVALENT BOND A strong bond formed when atoms share electrons in order to become more stable, forming a molecule. Strongest 2IONIC BOND An attraction between two oppositely charged ions, forming a compound. H2 molecule Bond Strength 3HYDROGEN BOND An attraction between the slightly positively charged hydrogen atom of one molecule and the slightly negatively charged atom of another. NaCl compound Weakest H2O H2O Chemical Bonds Rap Chemical Bond

25. The Human Element Activity • At your groups, decide who is your ‘model’ and dress them up in a trash bag. • You will be assigned an element, decide how many valence electrons it has and inflate and attach the correct number of balloons • Determine your ion, and create a tag to wear • Now BOND!

26. Periodic Trends Periodic Table In ascending atomic number (mass usually follows trend) Valence electrons can be determined by what group the atom is in Periods (horizontal) Groups (vertical) The total number of energy levels can be determined by the period Trend doesn’t work well for the transition elements

27. Alien Periodic Table by John Bergmann and Jeff Christopherson • NASA’s instructions: • Organize the aliens in a rectangular block. • Each group (vertical column) must be the same in some way and must have some feature that changes regularly as you move down the group. • Each period (horizontal row) must also share one thing in common and also must have one feature that changes regularly as you go across the periodic table.

28. Answer Key 1 2 3 4 5 6 7 8 2 3 4 5

29. Why is this one wrong? 1 2 3 6 7 8 1 2 3 4 5

30. Chemical Reactions The job of a chemical reaction is to depict the kind of reactants and products and the relative amounts in a reaction. Symbols represent elements, formulas describe compounds, and chemical equations describe a chemical reaction C + O2 = CO2 Reactants are what you use, products are what you get

31. Chemical Symbols The subscripts tell you how many atoms of a particular element are in a compound. The coefficient tells you about the number of molecules of the compound.

32. Balancing Reactions Due to the Law of Conservation of Mass: matter cannot be created nor destroyed. An equation must be balanced (it must have the same number and kinds of atoms both before and after a reaction. • When balancing a chemical reaction you may add coefficients in front of the compounds to balance the reaction, but you may not change the subscripts. • Changing the subscripts changes the compound. Subscripts are determined by the valence electrons (charges for ionic or sharing for covalent) Think of a recipe without any measurements Reaction Rate Demo

33. Elements with the same number of protons but different number of neutrons are called isotopes Isotopes Going back to those neutrons…

34. Neutron Nucleus Proton Proton + Nucleus + Neutron + + + Carbon-12 + + + + + + + Carbon-14 Isotopes Electrons Nucleus Electrons Neutrons 6 Protons 6 Electrons 6 As istopes decay, the release nuclear particles at a rate called a half life Neutrons 8 Protons 6 Electrons 6 Nucleus

35. Isotopes Knowing an atoms half life allows us to determine the age of organic items based on their relative amounts of isotopes Decay of Candium

36. Follow up • Q & A • Post Test • Give-a-ways • Extenstions • Symphony of Science • Powers of Ten • Khan Academy