1. CHAPTER 4. MATTER & ENERGY
CHM130 GCC

2. 4.1 Three States of Matter: solid, liquid, and gas
Gas: Particles are far apart and are in constant motion.
Gases have no set shape, they assume shape of the container.
Gases have no set volume, it is variable
If volume increases, particles move farther apart.
If volume decreases, particles move closer together.

3. Liquid: Particles are close together but are free to flow around one another.
Liquids assume shape of the container.
Volume is constant (can’t compress).
Solid: Particles are packed tightly together & organized in a rigid pattern; the atoms vibrate in place.
Solids have a definite, fixed shape.
Volume is constant.

4. Cool animations
3 States Of Matter – Scroll down and click on all the states of matter animations and the phase change animation (some may not work which is why there are several options)

5. Ways to Draw the States of Matter

6. physical changes – learn these 6 terms

8. 4.2 Definitions
Element – one type of atom only, can be single atoms (He) or diatomic molecules (O2), cannot be broken down further chemically
Compound – two or more different atoms bonded together, can be broken down chemically into elements
Pure – all particles are the same, cannot be physically separated
Mixture – two or more different particles mixed together, can be physically separated
(top picture is pure element, bottom is pure compound)

9. Examples Mixtures Metal alloys like 18-K gold, brass Sand, granite
Tap water
Air which consists of nitrogen, oxygen, and other trace gases.
Pure
Salt (NaCl) is a compound
Diamond (carbon) is an element
Distilled water is a compound
Mercury is an element

10. element
compound
mixture

11. A = element
B = cmpd
C = mix
D = element
E = cmpd
F,G = mix
H = element
For each figure, indicate if it represents an element, a compound, or a mixture

12. 4.3 Elements Each element has a unique name, symbol, and number
Capitalize first letter of element name: hydrogen H, carbon C
If there’s a 2nd letter it is lower case: helium He, calcium Ca, cobalt Co
Careful! CO is carbon monoxide not cobalt

13. Most symbols are from English names:
hydrogen H; oxygen O; Helium He
Some are from Latin names:
lead Pb (plumbum)
gold Au (aurum means “golden dawn”)

14. Ag silver Au gold Pb lead Br Bromine I iodine Hg mercury
KNOW THE NAMES AND SYMBOLS
OF THE FIRST 20 ELEMENTS
OF THE PERIODIC TABLE
& THE FOLLOWING
Ag silver Au gold Pb lead
Br Bromine I iodine Hg mercury

15. Let’s name them! Periodic Table: You already know many of these
Figure 04-05
Title:
Metals, Nonmetals, and Semimetals
Caption:
The symbols of elements having metallic properties are on the left side of the periodic table, nonmetallic are on the right side, and semimetallic are midway between. Notice the special placement of hydrogen, a nonmetallic element.
Notes:
The elements are classified by metallic character. Each class of element is shown in a distinct color.
Keywords:
periodic table, element, metal, semimetal, nonmetal, atomic number

16. 4.4 nonmetals, semimetals, and metals
(Fig. 4.5)
Nonmetals (except H) are located on the right side of the stair-step line
Semimetals are touching the stair-step line following B (except Al which is metal)
Metals are on the left side of the stair-step line

17. Properties of Metals vs. Nonmetals
shiny appearance
dull appearance
malleable, ductile
All solids but Hg
Brittle solids
Many gases
density – usually high
melting point - high
density – usually low melting point low
Good conductors of heat & electricity
Poor conductors (make better insulators)
Semimetals (metalloids) Have properties in between

18. Physical States of the Elements at 25 ˚C and normal atmospheric pressure
KNOW THESE
Only mercury (Hg) and bromine (Br2) are liquids
H2, N2, O2, F2, Cl2, and all Noble gases (Group VIIIA) are gases
All other elements are solids

19. Physical States of the elements
04_06.JPG
Figure 04-06
Title:
Physical States of the Elements
Caption:
At 25 °C and normal atmospheric pressure, all metals are in the solid state except Hg. Most nonmetals are gases except C, P, S, Se, and I, which are solids. The only elements in the liquid state at normal conditions are Hg and Br.
Notes:
The elements are classified by physical state at room temperature and atmospheric pressure. Each class of element is shown in a distinct color.
Keywords:
periodic table, element, solid, liquid, gas, state of matter

20. 7 Diatomic elements Diatomic means two atoms bonded together Have no fear of ice cold Beer!
H2(g) N2(g) F2(g) O2(g) I2(s) Cl2(g) Br2 (l)

21. Two Diatomic Elements Bromine Br2(l) and Iodine I2(s)

22. I should be able to point at any element and you tell me 1
I should be able to point at any element and you tell me 1. Solid, liquid, or gas 2. Name (for some of them) 3. Diatomic or not 4. Metal, semimetal, nonmetal Let’s play! I’ll point at several elements…

23. This is how we draw Atoms of an Element

24. 2 or more atoms bonded together =
Molecules of an Element if same
Molecules of a Compound if different

25. but it is not bonded K-N-O-O-O
4.5 Chemical formulas tell us
- type of atoms = element symbols
# of those atoms = subscripts (don’t show 1)
But NOT their bonding order
Ex: water = H2O 2 H atoms, 1 O atom
but water is not bonded H-H-O
Ex: How many atoms in potassium nitrate = KNO3
___ K, ___ N, ___ O atoms
but it is not bonded K-N-O-O-O 1 1 3

26. Another Example

27. What is the total number of atoms?
Ex: (NH4)3PO4
What is the total number of atoms?
How many atoms of each element are present in Viagra: C22H30N6O4S ?
____ C, ____ H, ___ N, ____O, _____S
(NH4)3 = 3 NH4’s = 3 ( 1 N + 4 H) = 3N + 12 H
TOTAL: 3 N, 12 H, 1 P and 4 O’s = 20 atoms 22 30 6 4 1

28. Law of Definite Composition
Compounds always contain the same elements in the same proportion by mass.
Ex: H2O always contains 11.2 % H and 88.8 % O by mass whether you have a glass full, a swimming pool or an ocean.

29. 4.6 Physical properties - color, odor, taste, texture, melting point, physical state (s, l, or g), density, solubility, conductivity, hardness
Chemical properties - describe how a substance reacts or behaves. (explosive, corrosive, toxic, inert, reactive, rusts, oxidizes, decomposes, etc.)

30. 4.7 Physical change: a change that keeps chemical composition the same, the molecules stay the same with the SAME formula. Physical Changes ARE changes in state (s D l D g) Ex: boiling water, melting gold, freezing alcohol, breaking glass, dissolving salt in water, dry ice subliming

31. Note that the H2O molecules remain H2O regardless of whether the sample is a solid, liquid, or gas; changes in physical state are physical changes

32. Review Physical Changes – know these terms!

33. Physical Changes Atoms are always moving, even in solid state.
When you heat ice, the water particles gain kinetic energy and move faster.
When particles gain enough energy to overcome attractive forces the solid will melt  liquid.
If we keep heating the liquid, the particles gain more KE & move even faster  gaseous state

34. Chemical Changes: a process that changes the chemical composition, the molecules break apart and rearrange. The formula CHANGES. (aka chemical reactions) Starting substance is destroyed and a new substance with different properties is formed.
Ex: burning gas

35. Indicators of chemical reaction: These may indicate chemical change
oxidation of matter (burning or rusting)
release of gas bubbles (fizzing) without heating (thus not boiling)
formation of solid (precipitation)
release of heat or light
change in color or odor

36. CHEMICAL REACTIONS REACTANTS  PRODUCTS
Starting substances are called reactants;
New substances formed are called products.
Ex: 2 H2 + O2  2 H2O

37. Ex: Chemical reaction between sodium metal Na(s) and chlorine gas Cl2(g). They produce salt, NaCl, which is a totally different chemical with different formula and properties than the reactants.

38. 4.8 LAW OF CONSERVATION OF MASS
Matter or mass cannot be created or destroyed
mass of the reactant(s) = mass of the product(s)
Two reactants make 4.0 grams of product. If one reactant was 1.5 grams, the other was ________
2.5 g

39. 4.9 Kinetic Energy - Energy of motion
Examples
Water flowing over a dam
Working out
Dancing
Burning gasoline

40. Potential Energy- Stored Energy
Examples
Water behind a dam
Gasoline or coal
Chemical bonds in food
Car at top of roller coaster

41. KE, Temp, and physical state
As kinetic energy increases and molecules move and vibrate faster, the temperature ____________. As kinetic energy increases a solid will eventually turn into a ____________. And as the KE increases even more it will eventually turn into a ____________.
KE and T are related directly or indirectly?
Which state of matter has lowest KE? Highest?
increases
liquid
gas
solid
gas

42. 4.10 Law of Conservation of Energy
Energy cannot be created or destroyed, only converted from one form to another.
Ex: When we digest food its stored energy (potential) is converted to kinetic energy to do work.

43. 6 Other Forms of Energy Radiant (light, UV, radiowaves, etc.) Heat
Chemical (stored in bonds)
Electrical
Mechanical
Nuclear

44. Chapter 4 Self Test Page 107 Try # 1, 4-11, 14-16
Answers in Appendix J