TAKS Objective 3

1
TAKS Objective 3

• Structures and Properties of Matter

NaBr HCl ? NaCl HBr
2
TAKS Objective 3 Overview

• 6 Questions out of 60.
• You need at least 5 right to pass this objective.
• Here is what you should know about Objective 3

• Chemical and Physical Properties of Substances
• Classifying Matter
• Identifying Compounds
• Chemical Reactions
• Periodic Table
• Chemical Equations

• Composition of Matter
• Atomic Structure
• Properties of Atoms
• Interactions Between Matter and Energy
• Interactions Between Matter and Energy
• Specific Heat

3
Matter

• Matter is anything that takes up space (volume)
  and has mass.
• Matter is classified in many ways.
• Matter in our everyday world is either solid,
  liquid, gas, or plasma.

4
Classifying Matter
How you could group these objects? Describe 2-3
ways.
5
By Color
yellow
blue
red
6
By the kinds of edges
curved edges
straight edges
7
by shape.
rectangles
triangles
circles
squares
8
Were you able to come up with 2-3 ways to sort
the objects? color shape edge Did you
find any different ways?
ideas?
9
Classifying Matter

• Physical and chemical properties can be used to
  identify and classify a substance.

10
You can observe and measure The physical
properties of matter.
sight
smell
taste
hearing
touch
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Physical Properties of Matter

• Color
• Odor
• Physical State
• Luster
• Malleability
• Ductility
• Conductivity
• Hardness
• Melting/Freezing Point
• Boiling Point
• Density
• Solubility

12
Chemical Properties of Matter

• The ability of a substance to change into a new
  substance.
• Flammability
• Ability to rust
• Ability to react with acids

13
Checkpoint 3.1, Classifying Matter

• Which lab procedure described below would
  provide information about the chemical properties
  of a clear liquid substance?
• A Cooling it to find its freezing temperature
• B Observing the rate at which it evaporates
• C Comparing its density to the density of water
• D Adding an acid to see whether a gas is produced

14
Periodic Table Overview
An element is a pure substance that cannot be
broken down into other substances. It is made of
only one kind of atom. The Periodic Table
organizes elements based on their properties.
15
3 Classes of Elements
Class Color
Metal
Non-Metal
Metalloid
16
Metals

• Location
• Found on the left of the zigzag line/staircase on
  the periodic table (exception ? Hydrogen)
• Chemical Properties
• Have few electrons in their outer energy level,
  thus lose electrons easily
• Physical Properties
• ductile, good conductors, malleable, shiny, most
  are solid _at_ room temperature

79 Au 196.967
11 Na 22.990
Image taken from http//chemistry.about.com/od/p
eriodictableelements/ig/Element-Photo-Gallery.--98
/Sodium.htm
What metal is not a solid _at_ room temperature?
17
Non-Metals

• Location
• Most found to the right of the zigzag
  line/staircase on the periodic table
• Chemical Properties
• Most have almost full outer energy levels, thus
  they tend to gain electrons some have
  completely full outer level
• Physical Properties
• not ductile or malleable, not shiny, poor
  conductors, most are solid, but some are gas at
  room temperature

17 Cl 35.453
Image taken from http//nobel.scas.bcit.ca/resou
rce/ptable/cl.htm
16 S 32.066
Image taken from https//www.dmr.nd.gov/ndgs/rock
andmineral/sulfur.asp
18
Metalloids

• Location
• Border the zigzag line/staircase on the periodic
  table
• Chemical Properties
• Most atoms have ½ () complete set of electrons
  in outer level
• Physical Properties
• have properties of both metals and non-metals

14 Si 28.086
Image taken from http//library.thinkquest.org/C
0113863/bios.shtml
5 B 10.811
Image taken from http//library.thinkquest.org/C
0113863/bios.shtml
19
Checkpoint 3.2, Periodic Table Overview

• Which of the following groups of elements
  from the periodic table contains only metals?A
  Group 12B Group 14C Group 16D Group 18

20
Atoms

• Atom- basic building block of all matter
• An atom is the smallest particle an element can
  be divided into and still be the same element.

21
Atomic Structure

• There are 4 main structures of an atom
• Shell, Cloud, Level
• Proton
• Electron
• Neutron

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HELIUM ATOM
Shell Cloud Level
proton
N

-

N
-
neutron
electron
What do these particles consist of?
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ATOMIC STRUCTURE
Particle
Charge
Mass
proton
positive charge
1
neutron
No charge
1
electron
negative charge
0
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ATOMIC STRUCTURE
Electrons are arranged in Energy Levels or Shells
around the nucleus of an atom.

• first shell a maximum of 2 electrons
• second shell a maximum of 8 electrons
• third shell a maximum of 18 electrons

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ATOMIC STRUCTURE
He
2
Atomic number
the number of protons in an atom
4
Atomic mass
the number of protons and neutrons in an atom
number of electrons number of protons
26
Checkpoint 3.3, Atomic Structure

• Which of the following best represents the
  structure of a lithium (Li) atom? A C
  B D

27
Important Features of the Periodic TablePeriod
(Row)

• each horizontal row of elements on the periodic
  table

How many periods (rows) are on the Periodic
Table Of Elements?
FROM LEFT TO RIGHT OR RIGHT TO LEFT
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Period (Row) Properties

• Seven periods on a periodic table (numbered from
  the top down)
• All atoms of the elements in the same period have
  the same number of orbitals/levels
• All atoms of the elements in a specific period
  have that respective number of orbitals/levels
• Example
• Period 1 1 orbital
• Period 2 2 orbitals
• Period 3 3 orbitals
• Etc

29
Examples of Period (Row) elements having the same
number of orbitals/levels in their atoms
In what period (row) do you think these atoms
reside?
In what period (row) do you think these atoms
reside?
30
Important Features of the Periodic Table Group
(Family)

• each column of elements on the periodic table

How many groups (families) are on the Periodic
Table Of Elements?
FROM TOP TO BOTTOM OR BOTTOM TO THE TOP
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Group (Family) Properties

• Eighteen groups on the periodic table (numbered
  from left to right)
• Atoms of elements in the same group have the same
  number of electrons in the outer orbitals/ levels
  of their atoms (known as valence electrons).
• Exceptions
• Transition elements (3-12)
• Hydrogen (could be 1 or 17)
• Helium (actually has 2 valence electrons)
• Elements in groups usually have similar physical
  and chemical properties.

32
Examples of Group Elements with the same of
valence electrons
How many electrons do each of these atoms have in
their outer orbital/level?
What group (family) do these elements reside in?
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Identify the Element
Period 2 Group 14 ?
Carbon - C
Period 5 Group 2 ?
Strontium - Sr
Group 17 Period 6 ?
Astatine - As
Group 4 Period 7 ?
Rutherfordium - Rf
34
Using the Periodic Table

• The boxes that make up the periodic table contain
  a significant amount of information. To
  understand this information, it is necessary to
  refer to the Periodic Tables key (s).

8 O Oxygen 15.999
Atomic Number (Number of protons)
Element Symbol (Written with a capital letter
followed by a lower case)
Class Color
Metal
Non-Metal
Metalloid
Element Name
Atomic Mass (Rounded to a whole number, equals
the number of protons and neutrons)
State (_at_ Room Temp.) Symbol Color
Solid
Liquid
Gas
What is Oxygens physical state of matter?
Which class does Oxygen fall into?
35
How to Obtain the Number of Sub-Atomic Particles
in an Atom Using a Periodic Table
-
-
-
8



O
-
-


Oxygen
-
15.9994
-
-
Protons
Neutrons
Electrons

-
Equal to the atomic mass (rounded to a whole )
minus the of protons
Equal to the atomic on the Periodic Table
Equal to the of protons
Example Determine the of protons, neutrons,
and electrons in an atom of oxygen. Protons 8
(Atomic ) Neutrons 8 (Rounded atomic
mass minus atomic ) Electrons 8 ( of
P) Neutron Calculations 16 (P N) 8 (P) 8 N
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Sodium-23 mass number
37
Carbon-12 mass number
38
Checkpoint 3.4, Properties of Atoms

• How many electrons does gold (Au) have?
• F 79
• G 118
• H 197
• J 276

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Elements, Molecules, and Compounds
Some elements, such as the noble gases, exist as
individual atoms.
Often, elements consist of two or more atoms
joined together. We call these molecules.
If more than one type of atom is in a molecule,
we call it a compound.
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Element or Compound?
methane, CH4
sulphur, S8
compound
element
(Click for answer)
(Click for answer)
hydrogen peroxide H2O2
sulphuric acid, H2SO4
compound
compound
(Click for answer)
(Click for answer)
oxygen (ozone), O3
carbon (buckyball), C60
element
element
(Click for answer)
(Click for answer)
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Mixtures
This is a mixture of elements made up of atoms,
elements made up of molecules, and compounds. In
a mixture, the particles are not joined together.
Atom, molecule or compound? (click for answer)
atom
Atom, molecule or compound? (click for answer)
molecule
Atom, molecule or compound? (click for answer)
compound
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Compounds

• Compounds are formed when atoms of different
  elements are combined.

• When the elements are combined their properties
  change.

43
Analogy

• Think of elements as letters of the alphabet and
  compounds as words formed by combining the
  letters.
• We can spell all of the English words with just
  26 letters.
• We can form millions of compounds with just 109
  elements.
• Ex Sodium(Na) Chlorine (Cl) Salt (NaCl)

44
Forming Compounds

• When compounds are formed Chemical changes occur.
• The compound does not have the same physical
  properties of its components.
• When combining two elements a new substance is
  formed?

45
Checkpoint 3.5 Identifying Compounds

• chlorophyll 6CO2 6H2O light energy
  ? C6H12O6 6O2 Plants use the suns energy to
  make food through photosynthesis. This chemical
  process is written as the chemical equation shown
  above. Which of the following lists the three
  elements that make up the compounds in this
  equation?A Chlorophyll, carbon, hydrogenB
  Carbon, sunlight, oxygenC Carbon, oxygen,
  hydrogenD Water, oxygen, hydrogen

46
Physical Change

• a change in shape, size, color, or state
• a change without a change in chemical composition
• a change that is reversible
• Examples
• tearing paper
• cutting your hair
• change in state

Physical changes are not indicative of a chemical
reaction
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Chemical Change

• a change in which a substance becomes another
  substance having different properties
• a change that is not reversible using ordinary
  physical means
• Changes that usually cause temperature change,
  sound, light, odor, bubbling/foaming, or color
  changes
• Examples
• mixing vinegar baking soda
• burning a piece of wood
• soured milk

48
Chemical Reaction

• The process by which a chemical change occurs
• Atoms are rearranged, and chemical bonds are
  broken and reformed
• Chemical reactions involve changes in matter, the
  making of new materials with new properties, and
  energy changes.

What does H2 O2 gas create?
O2
H2
49
Energy and Chemical Reactions

• Exothermic Reaction
• A chemical reaction in which energy is released.
• C6H12O6 6O2 ? 6CO2 6H2O energy
• (respiration)

• Endothermic Reaction
• A chemical reaction in which energy is absorbed.
• CO2 H2O energy ? C6H12O6 O2
• (photosynthesis)

Can you think of other reactions where energy is
gained or released?
50
Checkpoint 3.6 Chemical Reactions

• Which of the following situations contains
  an example of a chemical reaction?
• A Ice forming after water is placed in a
  freezer
• B Watercolor paint drying on paper
• C A sugar cube dissolving in a glass of water
• D A bicycle rusting after it is left in the
  rain

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Chemical Reactions

• Symbols represent elements
• Formulas describe compounds
• Chemical equations describe a chemical reaction.

Na
CH4
Na O2 ? Na2O
52
Chemical Equation

• Shorthand form for writing what reactants are
  used and what products are formed in a chemical
  reaction
• Sometimes it shows whether energy is produced or
  absorbed
• Examples
• 2H2 O2 ? 2H2O
• CH4  2O2 ?  CO2    2H2O
• C6H12O6 6O2 ? 6CO2 6H2O energy

53
Components of a Chemical Equation
Chemical Formulas
Chemical Formula
?
2H2 O2
2H2O
Subscript
Coefficient
Coefficient
Subscripts
(Yield)
(Products)
(Reactants)
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Subscripts vs. Coefficients

• The subscripts tell you how many atoms of a
  particular element are in a compound. The
  coefficient tells you about the quantity, or
  number, of molecules of the compound.

55
Law of Conservation of Mass
Mass is neither created nor destroyed during
chemical or physical reactions.
Total mass of reactants Total mass of products
Antoine Lavoisier
56
Chemical Equations

• Because of the principle of the conservation of
  matter,
• an equation must be balanced.
• It must have the same number of atoms of the
  same kind on both sides.

57
Law of Conservation of Mass

• Proposed by Antoine Lavoisier
• In a chemical reaction, atoms are neither created
  nor destroyed
• All atoms present in the reactants are also
  present in the products
• Chemical equations must account for/show the
  conservation of mass ? balancing equations

In its present form, does this chemical equation
show a conservation of mass?
H2 O2
H2O
?
2
2
Products
Reactants
How would you balance this equation to show the
conservation of mass?
H ? 2 O ? 1
H ? 2 O ? 2
4 2
4 2
58
Checkpoint 3.7 Chemical Equations

• The model shows the structural formula for
  methane. Which of these is the proper chemical
  formula for methane?
• F 4CH
• G CH 4
• H 2CH2
• J CH4

59
Cup gets cooler while hand gets warmer
Heat The flow of thermal energy from one object
to another.
Heat always flows from warmer to cooler objects.
Ice gets warmer while hand gets cooler
60
Specific Heat Is the resistance of a substance to
change in temperature. Some things heat up or
cool down faster than others.
Land heats up and cools down faster than water.
61
Specific heat is the amount of heat required to
raise the temperature of 1 kg of a material by
one degree (C or K). 1) C water 4184
J / kg C 2) C sand 664 J / kg C
This is why land heats up quickly during the day
and cools quickly at night and why water takes
longer.
62
Why does water have such a high specific heat?
water metal
Water molecules form strong bonds with each
other therefore it takes more heat energy to
break them. Metals have weak bonds and do not
need as much energy to break them.
63
A calorimeter is used to help measure the
specific heat of a substance.
64
Checkpoint 3.8 Specific Heat

• A person was driving across a hot desert in a
  car without air- conditioning. If all other
  factors were equal, the temperature inside the
  car would have been lowest if the car was A
  whiteB redC blueD black