Physical & chemical changes

1. Physical & chemical changes Time to change and rearrange the changes of change

2. 2 categories of change… • Physical change: any change that does NOT change the property of matter • Nothing new is made… • Chemical change: a change where something new is made • Chemical property: how a substances changes/reacts into something new • yarp

3. Physical or chemical change??? • Ripping paper • Burning paper • freezing water • Frying an egg • Melting iron • Dissolving sugar into water • Reacting acid with metal to make dangerous gas • Yarp

4. Tricky reminders… • Phase changes = physical changes • Solid liquid gas • Ice, water, steam all water • Dissolving =physical change • Sugar dissolved in water… still sugar and water • yarp

5. So much… never too much!!! • So much we could do an assignment • Yes… • To work…

6. Matter… Layers of matter is good

7. Element = simplest matter • Atom = smallest unit of an element • Elements are the building blocks of all matter • Over 100 of them. On the periodic table. • We use chemical symbols to represent them. • C = carbon • O = oxygen • Co = cobalt • Yrp = yarp Woa!!!! Capital letters first, then lower case. Co = cobalt… CO = carbon monoxide (carbon and oxygen)

8. H = hydrogen He = helium Li = lithium • C = carbon N = nitrogen O = oxygen • F = fluorine Ne = neon Na = sodium • Mg = magnesium Al = aluminum Si =silicon • P = phosphorous S = sulfur Cl = chlorine • K = potassium Ca = calcium Fe = iron • Cu = copper Ag = silver Sn = tin • I = iodine Au = gold Ni = nickel • Hg = mercury Pt = platinum Co = cobalt • Zn = zinc Br = bromine Pb = lead • As = arsenic U = Uranium Mn= manganese • Ba = barium Fr = francium Yp = yarpium • You should be able to give me the FULL NAMES or the CHEMICAL SYMBOLS for these elements!

9. Expect quizes… • Yes… practice time on the goodies of elements… sweetness

10. compounds Putting elements together

11. Compound: 2 or more different elements chemically combined • Can be broken down into simpler substances • examples • Water = hydrogen and oxygen • Table salt = sodium and chloride • Sugar = carbon, oxygen, and hydrogen • Caffeine = carbon, oxygen, hydrogen, and nitrogen • Molecule: smallest a compound can get… • yarp

12. Chemical formulas = shorthand way of writing compounds • Rules • 1. write down chemical symbol • 2. give a symbol a subscript in the lower right hand side for the # of atoms • 3. parenthesis: multiple atoms inside the (parenthesis) by the subscript on the outside of the parenthesis • yarp

13. examples • 1 carbon, 4 hydrogen • CO2 • H3PO4 • 3 carbon, 8 hydrogen, 3 oxygen • Mg(NO3)2

14. Elemental molecules = diatomic molecules • 2 atom molecules • 2 of the same atoms bonded together • How they are found in nature • Nitrogen = N2 • Oxygen = O2 • Fluorine = F2 • Chlorine = Cl2 • Bromine = Br2 • Iodine = I2 • Hydrogen = H2 • yarp

15. Finally • Pure substance: a substance made of only one type of material. • Can NOT be separated by physical means • Two types • Elements • compounds • So everything up to this point are pure substances… • Yarp that

16. Mixtures…. Putting it together… taking them apart…

17. Mixture: 2 or more substances physically mixed together • NOT chemically combined… • Any physical change can separate a mixture. • In mixtures substances keep their unique properties • Taste, how they react, etc… • yarp

18. Mixtures can be separated physically • Density/let it sit: let more dense things settle • Phase changes. • Boil salt water… water evaporates, salt remains • Magnetic properties • Filtering • Like coffee • Chromatography: dissolving separation • Physically separate • yarp

19. categories of mixtures • 1. heterogeneous mixture: not evenly mixed • Cereal, skittles • Any salad dressing/juice you mix before using • Because things settled • 2. homogeneous mixture: evenly mixed • Two types • A. Colloid: evenly mixed where the mixed particles do NOT dissolve. • The particles do not settle out either… cloudy usually • yarp

20. Homogeneous mixtures continued • Types of colloids • milk = solid and liquid mixed • Gelatin = solid and liquid mixed • Whipped cream = gas and liquid mixed • Smoke = solid and gas mixed • Fog = liquid and gas mixed • Yarp

21. All done for now!!!! • Practice time… time to practice.. • Sugar lab time… time to use da sugar… • Sweet!!!!!

22. Solutions…The other type of evenly mixed mixture… So popular we give it it’s own day

23. We learned about before… • A. Colloids… • Now… • B. Solutions: one substance dissolves into another. • Seems to “disappear” • Dissolve = the ability to go into solution • Something is physically broken down to the smallest pieces possible (atoms/molecules) • yarp

24. Show em how you remember… • Solvent = what things dissolve into • Solute = what gets dissolved into the solvent • Yarp

25. Identify the solute and solvent

26. Human plasma vs. human whole blood

27. Types of solutions Water is considered the universal solvent because so many things dissolve into it…

28. Soluble = will go into solution/dissolve • Insoluble = will NOT go into solution/dissolve • Solubility = how well things dissolve • What affects solubility???? • Yea… what makes things dissolve faster and slower??? • Yarp????

29. Affect rate/speed of solubility • 1. temperature • ↑ temp = ↑ solubility • ↓ temp = ↓ solubility • 2. surface area • ↑ surface area = ↑ solubility • ↓ surface area = ↓ solubility • 3. physical energy (stirring) • ↑ stirring = ↑ solubility • ↓ stirring = ↓ solubility • yarp

30. Woa… • We be done… yet another unit… a woo hoo man!!! • Hard core review… • Hard core mixtures and pure substances • To the extreme!