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STAAR Reporting Category 1Matter & Energy
Atoms and Elements
The Structure of an Atom
nucleus++
+ ++
+
Proton (+)
neutron (o)
electroncloud
electron (-)
Location and Mass of Atomic Particles
Inside the Nucleus
Protons with a POSITIVE
charge
AND
Neutrons with a NEUTRAL charge (no charge)
Both have about the same mass
Outside the Nucleus
Electrons with a NEGATIVE charge
VERY, VERY tiny and do not contribute to the mass of the atom
It takes 2000 electrons to equal the mass of one proton or neutron
Elements are listed on thePeriodic Table
Atomic Number
Number of PROTONS and determine which element the
atom is
Atomic Mass
the number of PROTONS + NEUTRONS
First, round the atomic mass to the nearest whole number
Round to 28
How do I calculate # of NEUTRONS???
Then, subtract the Atomic number (# protons) from the Atomic mass (total # protons
and neutrons
28 (Atomic mass)
-14 (Atomic number) 14 NEUTRONS
Is there an EASIER way to remember all of this?
All you have to do is remember:
A=P=E
M-A=N
A=P=E
Atomic Number = Protons = Electrons
If I know ONE, I know them
ALL!!
M-A=NMass
-
Atomic Number
=
Neutrons
Symbol Atomic #
Mass #
#Protons
#Neutrons
#Electrons
He 2 4 2
3 7 3 3
N 7 7 7
PRACTICE TIMEUse your Periodic Table!!
Li
2 2
4
7 14
Electrons and Bohr Diagrams
1) Find your element on the periodic table.
2) Determine the number of electrons – remember, it is the same as the atomic number.
3) This is how many electrons you will draw.
Bohr Diagrams
6 P6 N6 P6 N
Draw a nucleus with the number of protons and neutrons inside.
Bohr Diagrams
1) Add the electrons.
2) Carbon has 6 electrons.
3) The first shell can only hold 2 electrons. Always start in the first shell
6 P6 N6 P6 N
Bohr Diagrams1) Since you have 2
electrons already drawn, you need to add 4 more.
2) These go in the 2nd shell.
6 P6 N6 P6 N
Bohr Diagrams1) Check your work.
2) You should have 6 total electrons for Carbon.
3) Only two electrons can fit in the 1st shell.
4) The 2nd and 3rd shells can hold up to 8 electrons.
6 P6 N6 P6 N
Bohr Diagrams
Try the following elements on your own:
a) H
b) He
c) O
d) Al
e) Ne
f) K
Bohr Diagrams
Try the following elements on your own:
a) H – 1 electron
b) He
c) O
d) Al
e) Ne
f) Na
1 P1 P
Bohr Diagrams
Try the following elements on your own:
a) H
b) He - 2 electrons
c) O
d) Al
e) Ne
f) Na
2 P2 N2 P2 N
Bohr Diagrams
Try the following elements on your own:
a) H
b) He
c) O - 8 electrons
d) Al
e) Ne
f) Na
8 P8 N8 P8 N
Bohr Diagrams
Try the following elements on your own:
a) H
b) He
c) O
d) Al - 13 electrons
e) Ne
f) Na
13 P14 N13 P14 N
Bohr Diagrams
Try the following elements on your own:
a) H
b) He
c) O
d) Al
e) Ne - 10 electrons
f) Na
10 P10 N10 P10 N
Bohr Diagrams
Try the following elements on your own:
a) H
b) He
c) O
d) Al
e) Ne
f) Na - 11 electrons
11 P12 N11 P12 N
Valence Electrons
• Found on the outermost energy level
–Determine how an element will react chemically
Lewis Structures
How many valence electrons does nitrogen
have?
5
Learning Check
How many valence electrons in each atom?
Helium
Oxygen Sodium
2 6 1
Charges of Atoms
Most atoms have a NEUTRAL CHARGE since they have equal numbers of protons (+) and electrons (-).
Some atoms gain or lose electrons to become IONS.
IONS are not neutral and the atom becomes positively or negatively charged. Let’s see how this works...
++
++
+
in an atom,protons ( ) are inthe centerand electrons ( )are on the outside
+
++
++
+
only electrons ( )can be addedor taken away
++
++
+
this is an atom with5 electrons and
5 protons
++
++
+
the atom is neutral
net charge = zero
5 (-) and 5 (+) = zero charge (neutral)
++
++
+
6 (-) and 5 (+) = -1
charge = ?
++
++
+
3 (-) and 5 (+) = +2
charge = ?
WHEN REMOVING ELECTRONS
THE RESULTING CHARGE IS POSITIVE
neutral +1
THE RESULTING CHARGE IS NEGATIVE
neutral -2
WHEN ADDING ELECTRONS
Elements are substances:
• that cannot be broken down into other substances
• that are made of atoms with the same number of protons in the nucleus
Elements are ORGANIZED on the Periodic Table
Elements with similar properties are placed in the same group in the periodic table.
The stair-step line separates the elements into metals and nonmetals.
Groups of ElementsGroups of Elements
Alkali Metals
• Group 1, highly reactive, 1 valence electron
• Soft metals with low melting points
The Periodic Table of Elements
1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
Alkaline Earth Metals
• Group 2, reactive, 2 valence electrons
• Hard metals with high melting points
The Periodic Table of Elements
1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
Transition Metals
• Group 3-12, variable # of valence electrons
• Unpredictable, don’t follow “reactivity” rules
The Periodic Table of Elements
1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
Halogens
• Group 17, highly reactive, 7 valence electrons
• Form “salts”
The Periodic Table of Elements1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
Noble Gases
• Group 18, full outer shells (2 in He and 8 in others)
• NON-REACTIVE
The Periodic Table of Elements1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
Rare Earth Elements • Group 3, Period 6 and 7• Special group of transition metals• Many are synthetic and/or radioactive
The Periodic Table of Elements1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
Metalloids
• Non-metal elements that are conductors of heat and electricity
The Periodic Table of Elements1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
Periodic Trends• Elements are arranged into horizontal rows called
PERIODS• Elements within a period have the same number of
ENERGY LEVELSThe Periodic Table of Elements
1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
1 energy level
2 energy levels
3 energy levels
7 energy levels
6 energy levels
5 energy levels4 energy levels
• Elements are arranged in vertical columns called GROUPS – have same number of VALENCE ELECTRONS – share similar CHEMICAL properties
4 va
len
ce e
lect
ron
s
6 va
len
ce e
lect
ron
s
The Periodic Table of Elements1 18
1 H 2 13 14 15 16 17 He2 Li Be B C N O F Ne3 Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm YbAc Th Pa U Np Pu AmCm Bk Cf Es Fm Md No
2 va
len
ce
elec
tron
s
1 va
len
ce e
lect
ron
3 va
len
ce e
lect
ron
s
5 va
len
ce e
lect
ron
s
7 va
len
ce e
lect
ron
s
8 va
len
ce e
lect
ron
s
Metal Properties• Shiny solids
• Ductile (able to be stretched)
• Malleable (able to be shaped)
• Good conductors of heat and electricity
• Magnetic
Nonmetal Properties• May be solids, liquids or gases
• Dull, brittle solids
• Poor conductors of heat and electricity
• Non-magnetic
Metalloid Properties
• Nonmetals with properties of both metals and non-metals• Weak conductors of heat and electricity
Atomic Theory
Atoms are building blocks of elements
Atoms in each unique element are the same. (Ex: Every
oxygen element has the same # of protons)
Atoms are different from atoms of other elements (Ex:
Hydrogen has a different # of protons than oxygen)
Two or more different atoms bond in simple ratios to form
compounds (Ex: Hydrogen & oxygen can chemically combine to
form water- H2O )
Writing Chemical Symbols
1. First letter is capitalized
2. Second letter is lower case
3. NO period at the end
H Cl O Hg Fe Sn C He
Co or CO
Does it really matter?
Alloys for metals used in jet turbines
Co = cobalt
carbon monoxide ColorlessOdorlessPoisonous gas
carbon oxygen
COCompound
Compounds2 or More Elements
Chemically Combined
Oxygen
Hydrogen Hydrogen2-H: 1-O
Water
HH
O
Ratio 2:1
Formulas use element symbolswith subscript numbers
H2O
1 is notshown
Change the ratioChange the substance
2:2
H2O2
Subscript numbers
http://www.wonderquest.com/images/2003-08-08-peroxide.jpg
HydrogenPeroxide
No subscripts??
NaCl1Na 1Cl
How many elements?
Salt
2
Chemical Changes
A chemical change is a change in which both the physical and chemical properties of the original substance are changed. The new substance has new physical and chemical properties.
Burning is a chemical change.
A chemical change is the result of a Chemical Reaction.
A chemical reaction occurs when atoms separate, come together, or rearrange to form new substances with new properties.
Example of a Chemical Reaction
Reactant + Reactant Product (goes to)
carbon + oxygen carbon dioxide (has different properties)
C + O2 CO2
Is the product the same as the reactants?
No, the atoms have been rearranged.
For Example…A chemical reaction takes place during
photosynthesis.
6CO2 + 6H2O C6H12O6 + 6O2
Carbon dioxide reacts with water to form glucose (a sugar) and oxygen.
copper + oxygen copper oxide 2 Cu O2 2 CuO
Cu O CuO
Cu O CuO
balanced
2 copper atoms 2 copper atoms
2 oxygen atoms 2 oxygen atoms
in a molecule (O2)
2 copper atoms 2 copper atoms=balanced=
2 oxygen atoms 2 oxygen atoms
Since nothing is lost or gained, there is no loss or gain in mass (atoms).
You can say the equation is balanced.
The Law of conservation of mass states that matter cannot be created or destroyed in any chemical reaction
The atoms in the reactants are rearranged to form new compounds, but none of the atoms disappear, and no new atoms are formed.
HH
HH O O
Reactants Products
Remember that atoms don’t change in a chemical reaction.
• The number and kinds of atoms present in the reactants of a chemical reaction are the same as those present in the products. When stated this way, it becomes the law of conservation of atoms.
So: Chemical equations are balanced, when the numbers and kinds of atoms on each side of the reaction arrow are equal.
H
H
HH O O
Reactants Products
HH
HH
OO
4 Hydrogen 4 Hydrogen
2 Oxygen 2 Oxygen
Coefficients, the numbers placed in front of formulas to balance equations, indicate the number of particles present in the reaction. If a number is not present it is understand that 1 is the coefficient. 2 H2 + O2 2 H2O
2
Notice that the number of hydrogen and oxygen atoms are equal
2
The number of oxygen atoms are not the same so the equation is balanced with coefficients.
The same number of each kind of atom must be on the left side of the arrow as are on the right side when an equation is balanced.
Al Al
Al Al
O O
O OO O
AlAlAlAl
O OO O
O O
When an equation is balanced the number of reactant atoms will always equal the number of product atoms and atoms are conserved
Al AlOO O
Al AlOO O
Chemical Equations• Many times it may seem that things we use disappear
over time. For example, gasoline in the car.• Elements of gasoline are merely re-arranged through
a chemical reaction. Gasoline CO2 and H2O• The number of each type of element and their masses
remain unchanged (balanced) in a chemical reaction. (Law of Conservation of Mass)
• A chemical equation is a way to describe or represent what goes on in a chemical reaction and follows the Law of Conservation of Mass.
• Matter cannot be created or destroyed – ONY rearranged into different substances.
Chemical and Physical Change
Organic Compounds
• Compounds that includes CARBON along with other element(s) hydrogen, nitrogen, phosphorous, and or sulfur.
• Nucleic Acid (DNA), Carbohydrates, Proteins, & Starch.
Is it Organic?C6H12O6
Ca3Si2O7
NaCl
C3H8
Fe2O3
YES
no
no
YES
no
C5H11NO2S
CuSO4
CH3COOH
Ca5(PO4)3OH
C27H46O
YES
no
YES
no
YES
The transfer of energy from the sun to producer to primary consumer to
secondary consumer to tertiary consumer can be shown in a FOOD
CHAIN.
The arrow shows the flow of energy, first from the sun to the producers
and then to each organism in the food chain.
Food Webs:
• Are interconnected food chains
• They show the feeding relationships in an ecosystem
• Arrows point in direction of energy flow
Another way of showing the transfer of energy in an ecosystem is the
ENERGY PYRAMID.
Energy pyramids show • That the amount of available
energy decreases down the food chain
• Only 10 % of the energy is passed to the next level
• It takes a large number of producers to support a small number of primary consumers
• It takes a large number of primary consumers to support a small number of secondary consumers
100%
10%
1%
.1%
What is density?
• Density is a comparison of how much matter there is in a certain amount of space.
What is density?
• Density = mass OR mass ÷ volume.
volume
• Units for density: g
cm3
OR
g
mL
ALWAYS REMEMBER UNITS!
Density Problems• Frank has a paper clip. It has a mass of 9 g and a
volume of 3 cm3. What is its density?
• Frank also has an eraser. It has a mass of 3 g, and a volume of 1cm3. What is its density?
D = m v
D = 9 g
3 cm3D = 3 g/cm3
D = m v
D = 3 g
1 cm3D = 3 g/cm3
• Jack has a rock. The rock has a mass of 6 g and a volume of 3 cm3. What is the density of the rock?
• Jill has a gel pen. The gel pen has a mass of 8 g and a volume of 2 cm3. What is the density of the pen?
D = m v
D = 6 g
3 cm3D = 2 g/cm3
D = m v
D = 8 g
2 cm3D = 4 g/cm3
• Al’Licia has a watch. It has a mass of 4 g and a volume of 2 cm3. What is the density of the watch?
• Mia has a wallet. It has a mass of 15 g and a volume of 5 cm3. What is the density of the wallet?
D = m v
D = 4 g
2 cm3D = 2 g/cm3
D = m v
D = 15 g
5 cm3D = 3 g/cm3
√ Check yourunderstanding
Use your
Periodic
Table
1. The symbol for carbon is –
A Ca
B c
C CA
D C
2. How many protons are in an atom of sodium?
A 11
B 12
C 23
D 34
3.How many neutrons are there,if the mass number is 1 andthe atomic number is 1?
A 3
B 2
C 1
D 0
4.How many electrons are inan atom of Cl?
A 17
B 18
C 35
D 0
5.Which of the following isa chemical formula?
A H
B O
C H2O
D h2o
6.How many different elements are in baking soda, NaHCO3 ?A 6
B 5
C 4
D 3
7. 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
C6H12O6 + 6 O2 6 H2O + 6 CO2
HCl + NaOH H2O + NaCl
8. Based on the data above, which statement is not true about chemical equations?
A. Products are the rearrangement of atoms from the reactants.
B. There are always more atoms on the reactant side of the equation than the product side.
C. The types of atoms in the products will be the same as the types of atoms in the reactants.
D. The mass and number of reactant atoms always equals the mass and number of product atoms.
9. Which chemical reaction is balanced?
A. C + O2 2 CO2
B. 2 C + O2 2 CO2
C. 2 C + 2 O2 2 CO2
10. Which chemical reaction is balanced?
A. HBr + Mg H2 + MgBr2
B. 2 HBr + Mg H2 + MgBr2
C. 2 HBr + 2 Mg H2 + 2 MgBr2