Download Warm-up #11 Jan. 25

WARM-UP
 Atomic


#11
JAN. 25
Theory
States that matter is composed of discrete
units called atoms
The word "atom" comes from the ancient
Greek adjective atomos meaning 'indivisible’
Essential Question:
When and where do you think mankind
originally began to ponder as to what makes
up the elements and atoms?
SUBATOMIC PARTICLES
Name
Symbol
Charge
Relative
mass
1/1840
Actual
mass
Electron
e-
-1
Proton
p+
+1
1
1.67 x 10-24
Neutron
n0
0
1
1.67 x 10-24
crap
9.11 x 10-28
SYMBOLS

The symbol of an element contains the mass
number and the atomic number:
Mass
Number
Atomic
Number
SYMBOLS
Find the:
1. Number of Protons
2. Number of Neutrons
3. Number of Electrons
4. Atomic Number
5. Mass Number
Rh
104
45
Rhodium - 104
HISTORY OF THE ATOM
The original idea of the atom came from Ancient
Greece (400 B.C.)
 Democritus – Greek Philosopher
 He and his mentor Leucippus
first described that all things were
made up of “atoms”

WHO’S NEXT?
Late 1700’s – John Dalton – England
 Teacher – summarized results of his experiments
and those of others in his Atomic Theory.
 His idea combined ideas of elements with atoms

DALTON’S ATOMIC THEORY
All matter is made up of tiny individual particles
called atoms
 Atoms of the same element are identical, those of
different elements are different
 Atoms of different elements combine in whole
number ratios to form compounds
 Chemical reactions involve the rearrangement of
atoms. No new atoms are created or destroyed.

JJ THOMSON
J.J. Thomson – English physicist, 1897
 Made a piece of equipment that explored the
properties of cathode rays.
 Basically discovered that atoms of divisible

THOMSON’S MODEL
Found the electron
 Couldn’t find positive (for a while)
 Said the atom was like plum pudding
 A bunch of positive stuff, with the electrons able
to be removed

PROTONS
 Proton
– positively charged pieces 1840
times heavier than the electron.
 Eugene Goldstein used a modified cathode
ray
 Rutherford predicted its presence in the
atom with gold foil experiment
RUTHERFORD’S EXPERIMENT
Ernest Rutherford was an English Physicist (1910)
 Believed in the plum pudding model of the atom.
 Wanted to see how big they are
 Used radioactivity
 Alpha particles – positively charged pieces given
off by uranium
 Shot them at gold foil which can be made a few
atoms thick

HE EXPECTED
The alpha particles to pass through without
changing direction very much.
 Because…
The positive charges were spread out evenly.
Alone they were not enough to stop the alpha
particles

WHAT HE GOT
HOW HE EXPLAINED IT
Atom is mostly empty
 Small dense, positive
 Piece at center
 Alpha particle are deflected by it if they get close
enough

DENSITY OF THE ATOM
Since most of the particles went through, it was
mostly empty
 Because the pieces turned so much, the positive
pieces were heavy
 Small volume, big mass, big density.
 This small dense positive area is the nucleus

BOHR’S MODEL – 1915
Why don’t the electrons fall into the nucleus?
 Move like planets around the sun.
 In circular orbits at different levels
 Amounts of energy separate one level from
another

BOHR’S MODEL
The further an electron is from the nucleus the
more energy it has
 There is no “in between” energy
 It is like a ladder

BOHR’S IS NOT RIGHT EITHER!
Bohr got closer than we had been so far, but it
was still not right.
 He gave us the idea of energy levels for electrons.
 BUT his idea only worked for one atom

NEUTRONS
No charge
 Same mass as the proton
 Discovered by James
Chadwick during
radioactivity experiments
in 1932

QUANTUM MECHANICAL MODEL
1925 - Erwin Schrondinger used the results of
the experiments done with the hydrogen atom to
come up with the quantum mechanical model
 This comes from a mathematical solution to the
Schrodinger equation
 The quantum mechanical model determines the
allowed energies an electron can have and how
likely it is to find the electron in various
locations.

QMM
Has energy levels for electrons
 Orbits are not circular
 It can only tell us the probability of finding an
electron a certain distance from the nucleus.

MODERN VIEW
The atom is mostly empty space
 Two regions
 Nucleus – protons and neutrons
 Electron cloud – region where you might find an
electron

ATOMIC THEORY TIMELINE ASSIGNMENT
You are to create a timeline that maps out each
significant event throughout history that involves
the atomic theory.
 There will be at least 8 events (all were covered in
the notes)
 For each event I want the:

Date
 Person
 What they contributed (IN COMPLETE SENTENCES).
 A drawing or something of what they discovered. They
need to be colored.

TICKET OUT THE DOOR
1.
2.
3.
4.
What does the atomic number tell you
about an element?
What are the three subatomic particles,
their relative masses, relative charges,
and location(which region of the atom)?
What is a compound?
What is an isotope?
WARM-UP
#12
JAN. 26
An ion is an atom or molecule in which the total
number of electrons is not equal to the total number
of protons

Cations

When an element
becomes positively
charged it forms a
cation

Anion

When an element
becomes negatively
charged it forms an
anion
What do you have to lose in order to
become positively charged?
THE PERIODIC TABLE
The periodic table is based on the Modern
Periodic Law
 Came from the QMM
 Set up in rows called periods



Indicate the main energy level
Columns called groups or families

Similar properties
 Dmitri
Mendeleev was one of the first
scientists to realize there was a trend in
the properties of the elements
CLASSIFYING
We separate the periodic table several ways to
help classify the elements
 This includes dividing it by families, and type of
element

Representative – group A
 Transitions – group B

We split the table into these 2 major groups
 Most of what we deal with deal with is in group A or
the representative elements

METAL ~ NONMETAL ~ METALLOID
These are three of our other main classifications
 Elements that fit into these groups have specific
properties

METALS

Most metals are solid at room temperature
Which one is the exception?
 Mercury – Hg


Generally good conductors of heat and electric
current

Sea of free floating electrons
Usually form cations
 Usually malleable and ductile

NONMETAL
Less similarities in the nonmetals
 Typically poor conductors of heat and electric
current
 Solid nonmetals tend to be brittle


Carbon, Sulphur
METALLOID
These elements have properties that are similar
to both metals and nonmetals
 Semiconductors



Can be used to produce superconductors
Boron, silicon, arsenic
PERIODIC TABLE ASSIGNMENT
Pick 3 elements, one from each subgroup (metal,
nonmetal, metalloid)
 Research each element:

Draw the symbol as you would see it on the periodic
table
 Label the atomic number and mass number
 Tell me where the element is found and how we use it


Products, industry, etc.
Describe some of its properties
 Draw a picture of what it looks like naturally
 These should be colored

WARM-UP


#13
JAN. 27
Valence Electrons - are the electrons of an
atom that can participate in the formation of
chemical bonds with other atoms.
Electron dot diagrams - diagrams that show
the bonding between atoms of a molecule and the
lone pairs of electrons that may exist in the
molecule
HOW DO ELEMENTS FORM IONS AND WHY?

All elements are trying to get the same number
of electrons as the nearest noble gas


Far column on the right
This is where valence electrons come in
VALENCE ELECTRONS
All atoms have valence electrons
 These are the electrons responsible for forming
bonds
 They are the furthest from the nucleus
 They fill the outermost energy level
 These determine the properties of the atom, such
as stability.

 Every
element can only have 8 valence
electrons
 They WANT to have 8 like the noble gases
 Helium only has 2 electrons TOTAL, so
some elements are content
VALENCE ELECTRONS

You can determine how many valence electrons
for Group A by looking at the groups number
VALENCE ELECTRONS


We represent valence electrons using electron dot
diagrams.
Electron dot diagrams show the element symbol
with dots representing the valence electrons
BOHR’S MODEL
 Shows
 1st
ALL of the element’s electrons
– 2e 2nd – 8e 3rd – 18e 4th – 32e-
NITROGEN
N
ALUMINUM
Al
IONS
Atoms
form ions based on the
number of valence electrons
Group VIII A
8
valence electrons (8 ve-)
What
0
is the charge as an ion?
 Positive
ions are called cations
These are formed when an atom loses
electrons
 The metals usually form cations

 Negative
ions are called anions
These are formed when an atom gains
electrons
 The nonmetals usually form anions

When
an atoms forms an ion it
changes size because it becomes
stable
 Cations
are much smaller the atom
in which they form
 Anions are much bigger than the
atom from which they form
TICKET OUT THE DOOR
1.
2.
3.
4.
What does the atomic number tell you
about an element?
What are the three subatomic particles,
their relative masses, relative charges,
and location(which region of the atom)?
What is a compound?
What is an isotope?
PRACTICE
 Draw
e- dot diagram, bohr model diagram,
and tell what charge each will have as an
ion







Sodium
Sulfur
Silicon
Oxygen
Argon
Chlorine
Beryllium
WARM-UP
Draw
#14
JAN. 30
e- dot diagram, bohr model
diagram, and tell what charge
each will have as an ion:
 Fluorine
 Neon
 Carbon
REVIEW
 What
are your three subgroups of
elements on the periodic table?
Metals
 Non-metals
 Metalloids

 What

is an isotope?
Atoms that have the same number of protons
but different number of neutrons.
REVIEW

What the atomic number equal to?


What is the mass number equal to?


Number of protons
Number of protons and neutrons
What is a valence electron?

Electron found on the out shell of an atom. There can
only be 8 total.
TYPES OF CHEMICAL BONDS

Ionic Bonds
Form between positive and negative ions
 Ex: salt forms when sodium reacts with chlorine


Covalent Bonds
Form when atoms share electrons
 Ex: Silicon dioxide forms when one silicon atom and
two oxygen atoms share electrons in that outermost
energy level


Metallic Bonds

Form when electrons are shared by metal ions
MINERALS
A mineral is a naturally occurring, inorganic
solid with an orderly crystalline structure and
definite chemical composition.
 There are nearly 4000 known minerals

NATURALLY OCCURRING
A
mineral forms by natural geologic processes.
 Synthetic gems are not minerals
SOLID SUBSTANCE
Minerals are solids within the temperature
ranges that are normal for Earth’s surface
 Definite shape
 Definite volume

ORDERLY CRYSTALLINE STRUCTURE

Their atoms or ions are arranged in an orderly
and repetitive manner
DEFINITE CHEMICAL COMPOSITION
Every mineral is made up of a specific compound.
Each sample of that mineral is made of the same
compound.
 Different minerals are different compounds
 Ex: Quartz – Si02

GENERALLY CONSIDERED INORGANIC
 What
do you think it means to be
organic?

Organic means that it is a compound
containing carbon
 Most
minerals do not contain carbon
 We say generally because there are
some animals that secrete
compounds considered minerals

Ex: Calcite : calium carbonite
SOURCE
http://www.rocksandminerals
.com/uses.htm
TICKET OUR THE DOOR
1.
2.
3.
4.
What is a mineral?
Give me two characteristics a mineral must have.
Give an example of a mineral and one of its uses.
Draw an e- dot diagram and Bohr model for
Phosphorus
1. LOCATED IN GROUP 5A
WARM-UP
 What
are five
characteristics
of a mineral?
#15
JAN. 31
 Coal
forms from
ancient plant
matter that has
been compressed
over time. Do
you think coal is
a mineral?
HOW MINERALS FORM
 There
are four major processes by
which minerals form:
 Crystallization from magma
 Precipitation
 Changes in pressure and
temperature
 Formation from hydrothermal
solutions
CRYSTALLIZATION FROM MAGMA
Magma is molten rock
 As magma cools, elements
combine to form minerals
 First minerals are usually rich in
iron, calcium, and magnesium.
 As minerals continue to form the
magma changes composition
forming minerals rich in sodium,
potassium, and aluminum

PRECIPITATION
Water contains dissolved substances
 As the water evaporates some of the dissolved
substances can react to form minerals.
 Limestone and Halite are common examples of
precipitation

PRESSURE AND TEMPERATURE
Some minerals form when existing minerals are
subjected to changes in pressure and
temperature
 An increase in pressure can cause a mineral to
recrystallize while still solid
 Atoms are rearranged
 Temperature change can cause minerals to
become unstable and form new minerals that are
stable at the new temperature.

HYDROTHERMAL SOLUTIONS
100° C – 300° C
 Very hot mixture of water and dissolved
substances
 When they come into contact with existing
minerals, chemical reactions take place and form
new minerals
 Minerals can also form when these solutions cool

MINERAL GROUPS

There are 6 groups of minerals that we will
discuss






Silicates
Carbonates
Oxides
Sulfates/Sulfides
Halides
Native Elements
SILICATES
Most common
 Contain silicon-oxygen tetrahedron
 Groups based upon tetrahedron arrangement







Olivine
Pyroxene
Amphibole
Micas
Feldspars
Quartz
OLIVINE

Independent tetrahedron
PYROXENE GROUP

Tetrahedrons are arranged in chains
AMPHIBOLE GROUP

Tetrahedron are arranged in double chains
MICAS
Tetrahedron are arranged in sheets
 Two types

Biotite – dark
 Muscovite - light

FELDSPARS
Three-dimensional network of tetrahedron
 Two types:

Orthoclase
 Plagioclase

QUARTZ

Three dimensional network of tetrahedron
CARBONATES
A major rock-forming group
 Found in the rocks limestone and marble
 Calcite and Dolomite are carbonate minerals

OXIDES
Minerals that contain oxygen and one or more
other elements.
 Rutile – TiO2 form as magma cool
 Corundum – Al2O3 forms when existing minerals
are subjected to changes in temperature and
pressure

SULFATES AND SULFIDES

Minerals that contain sulfur
Anhydrite – CaSO4
 Gypsum
 Pyrite – fools gold

HALIDES
Minerals that contain a halogen
 Salts
 Halite – table salt
 Fluorite

NATIVE ELEMENTS

Group of minerals that exist in relatively pure
form






Gold
Silver
Copper
Sulfur
Diamond
Graphite
WARM-UP
#16
FEB. 1
 Think
of and list as many properties as
you can that help us identity minerals.
Again, these are different than the
characteristics of minerals.
 Why
is it important to identify minerals?
MINERAL PROPERTIES


Minerals are classified by a set of specific
properties
These are considered intensive properties

This means they don’t depend on the amount of the
substance, but the composition instead
COLOR
Color is the first thing you will notice about a
mineral
 Do you think this is a good indicator of what a
mineral is made of?
 Not always
 A very small difference in amount of elements
present can change the color of the mineral

LUSTER
Luster describes how light is reflected off the
surface of a mineral
 Minerals that have the appearance of metals are
said to be metallic.
 Nonmetallic luster is described in many different
ways:

Vitreous
 Glassy
 Pearly
 Silky
 Earthy
 Adamantine
 Sub-metallic

STREAK
Streak is the color of a mineral in its powdered
form.
 You can obtain this by rubbing a mineral across a
streak plate (unglazed porcelain)
 Streak does not usually vary even if the color
does

CRYSTAL FORM

Visible expression of the internal arrangement of
atoms
HARDNESS
A
measure of the resistance of a
mineral to being scratched
 One
of the most useful properties in
identifying minerals
 We
use the Mohs scale of hardness
CLEAVAGE AND FRACTURE
Cleavage
and fracture both deal
with how a mineral breaks apart
Cleavage is the tendency to
break along a flat even surfaces
Fracture is the uneven
breakage of minerals
 Mica
shows cleavage; breaking in
even flat sheets
FRACTURE
DENSITY
Density is a property of all matter that is the
ratio of an object’s mass to its volume.
 Think of it as how compact the substance is

Grams
Cubic
centimeters
or
milliliters
PRACTICE
A
6.75 g solid with a volume of
5.35 cm3. Find the density.
D = 6.75g / 5.35 cm3
 D = 1.26 g/cm3
OTHER PROPERTIES
 Some
minerals have distinctive
feels

Talc is soapy, and graphite feels greasy
 Some
minerals are magnetic like
magnetite
 Some have distinctive smells like
sulfur
 Calcite reacts chemically with
hydrochloric acid and will fizz
REFLECTION
In your journals, tell me what you did today and
how it is important.
 Describe the different properties of minerals and
how you used them today to determine the
identity of various minerals.
 What were some properties of specific minerals
that gave their identity away relatively easily.

WARM-UP


#17
FEB. 2
What are the differences between ionic bonds,
covalent bonds, and metallic bonds? (use your
notes)
What are halogens?
TICKET OUT THE DOOR
Name 4 properties of minerals used for
identification.
 How do we calculate density?
 What is the difference between cleavage and
fracture?
