The Nature of Matter

1
The Nature of Matter

• Physical Sciences

2
Benchmarks

• A. Describe that matter is made of minute
  particles called atoms and that atoms are
  comprised of even smaller components. Explain
  the structure and properties of atoms.
• B. Explain how atoms react with each other to
  form substances and how molecules react with each
  other or other atoms to form even different
  substance.
• C. Describe the identifiable physical properties
  of substances (e.g., color, hardness,
  conductivity, density, concentration, pH, and
  ductility). Explain how changes in these
  properties can occur without changing the
  chemical nature of the substance.
• H. Trace the historical development of
  scientific theories and ideas, and describe
  emerging issues in the study of physical sciences.

3
Defining Matter
Matter - anything that has mass and takes up
space. Mass - the total amount of material in an
object. Tool to measure - triple beam
balance Units - mg, g, kg, etc.
4
Defining Matter

• Volume - the amount of space an object occupies.
• The volume of liquids can be measured using a
• graduated cylinder or beaker.
• Units are liters (L) or milliliter (mL).
• The volume of irregular shaped objects are
  measured using water displacement with a
  graduated cylinder or beaker.
• Units are liters (L) or milliliter (mL).

5
Defining Matter

• The volume of a cube can be calculated by
  measuring the length of one side using a
  meterstick or ruler.
• V length X height X width
• Ex. If the length of one side of a cube is 2
  cm, what is the volume?
• V 2 cm X 2 cm X 2 cm
• V 8 cm3

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Defining Matter

• Density - the amount of matter in a given space.
• D mass / volume
• Mass and volume both need to measured separately!
  The calculation (ratio) of the two measurements
  equals the density.
• Ex. If the mass of a cube is 54 grams and the
  length of a side is 3 cm., what is the density of
  the cube?
• First solve for volume V L X h X w
• V 3cm X 3cm X 3cm
• V 27 cm3
• Density mass 54 g 2
  g/cm3
• volume 27 cm3

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Chemistry

• Elements - the building blocks of matter, a pure
  substance, made up of one type of atom.
• Atom - the smallest particle of an element that
  has the properties of that element.
• Substance - made up of one or more elements.
• Compound - a combination of two or more atoms
  that maintains its own properties.
• Molecule- smallest particle of a substance that
  retains all the properties of the substance and
  is composed of one or more atoms.
• Composition - what matter is made of and how it
  is organized

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Chemistry

• Properties - describes the characteristics,
  composition and behavior of matter, including the
  changes that matter undergoes.
• 1. Physical - characteristics that a sample of
  matter exhibits without any change in its
  identity. Solubility, melting point, boiling
  point, color, density, electrical conductivity,
  physical state.
• 2. Chemical - can be observed when there is a
  change in the composition of the substance. Iron
  at room temp with air iron oxide (rust).
• Chemical formula- shows the number and kind of
  elements in a substance
• 2NH3
• Coefficient subscript
• (number of molecules)
  (number of atoms)

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Classifying Reactions

• Synthesis Reaction- Reaction in which two or more
  substances combine to form a compound. 2Na
  Cl2 ------ 2NaCl
• Decomposition Reaction- Compound breaks into two
  or more substances. 2HgO ------ 2Hg O2
• Single Replacement Reaction- One element replaces
  another element in a compound to form a new
  compound
• Fe CuSO4 ----- FeSO4 Cu
• Double Replacement Reaction- Occurs when two
  compounds in a reaction exchange ions
• AgNO3 NaCl ----- AgCl NaCO3

10
History

• Greek philosophers (Democritus) created theories
  about indivisible matter Atomos - meaning
  that which cannot be cut or divided.
  
• Aristotle theorizes that everything is composed
  of Earth, Water, Air, and Fire.

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History

• Early 1800s, John Dalton created the atomic
  theory (4 parts)
• 1. All elements are made up of atoms. Atoms
  cannot be created, divided,or destroyed.
• 2. All atoms of the same element have the same
  size and mass.
• 3. Atoms of different elements have different
  sizes and masses.
  
• 4. During a chemical reaction, atoms are not
  destroyed, just rearranged.
• Nuclear power disproves theorem number one.
  (Fission and Fusion)

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Periodic Table
13
The Periodic Table

• 1869 Periodic table began to be organized by
• Dmitri Mendeleev.
• He organized elements due to physical and
• chemical characteristics.
• 1. This was later called atomic number
• a. number of protons
• b. number of protons determines
  of
• electrons
• 2. Periodic repetition of properties
• www.chemicalelements.com/

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The Periodic Table

• 3. Elements in columns are called groups or
  families
• a. Total of 18 groups
• b. Groups have same characteristic and
  of valence electrons
• 1. Ve- electrons in outer shell
• c. as elements descend atoms grow larger
• 4. Elements in rows are called series or periods
• a. elements are arranged by inc. of
  protons (atomic )
• b. Total of 7 periods
• c. Descending periods increase electrons
  in shells. This is due to increasing mass.
• d. As one goes across period atoms grow
  smaller.This is due to force of charge pulling
  in electrons.

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Atomic Mass and Numbers
Atomic Number number of protons Number of
protons determines the number of electrons in
a neutral atom.

• Atomic Mass number of protons and
• neutrons
• Atomic mass minus atomic number
• equals the number of Neutrons.

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The Periodic Table
Atomic Number

• 3
• Li
• Lithium
• 6.941

Lithium Protons3 Electrons3 Atomic
Mass6.941 Neutrons4
Symbol
Name
Atomic mass
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Element Sizes
18
Electron Configurations

• These are the most stable arrangement of
  electrons
• There are 4 regions s,p,d,f
• s holds total of 2 electrons ___
• p holds total of 6 electrons ___
  ___ ___
• d holds 10 electrons ___ ___ ___
  ___ ___
• f holds total of 14 electrons ___
  ___ ___ ___ ___ ___ ___
• Shells will fill up one at a time (like seats on
  a bus)

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Electron Configurations

• Most stable arrangement of electrons
• 1s2
• -The large number "1" refers to the principle
  quantum number "n" which stands for the energy
  level.  It tells us that the electrons of helium
  occupy the first energy level of the atom.
• -The letter "s" stands for the angular momentum
  quantum number "l".  It tells us that the two
  electrons of the helium electron occupy an "s" or
  spherical orbital.
• -The exponent "2" refers to the total number of
  electrons in that orbital or sub-shell.  In this
  case, we know that there are two electrons in the
  spherical orbital at the first energy level.
• Oxygen O 1s22s2 2p6

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Bohr Models

• Model that illustrates subatomic particles for an
  element
• Step 1 calculate total number
• subatomic particles
• Step 2 Create the nucleus by
• drawing protons and
• electrons
• Step 3 Create electron shells
• and attach the correct
• amount of electrons
• Step 4 Label all particles and
• shells

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Particle behavior

• Hunds Rule electrons are negative, they have
  same charge and repel from each other, as far
  apart as possible.
• Heisenberg Uncertainty Principle 1920,
  impossible to measure accurately both the
• position and energy of an electron at the
• same time.

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Atomic Structure

• Subatomic Particles the particles below the
  surface of an atom. This includes protons,
  neutrons and electrons. An electrical force
  between nucleus and electrons holds the atom
  together.
• atom smallest particle of an element that has
  the chemical properties of that element.
• 1. a billion atoms laid end to end would
  make a line only 10cm long
• 2. atoms make up cells

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Atomic Structure

• A. electron negatively charged particle orbits
  the nucleus
• 1. electron is first to be discovered - 1891
• 2. lightest subatomic particle
• B. proton positively charged particle
• 1. located in nucleus of atom - 1896
• 2. second lightest subatomic particle
• C. neutron neutrally charged particle
• 1. located with proton in nucleus - 1932
• D. nucleus holds protons and neutrons of atom
• 1. discovered in 1910
• 2. atoms are mostly empty space,distance
  between nucleus and electron is like a marble on
  the pitchers mound of a baseball field and the
  furthest seat in the stadium would be the
  electron.

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Atomic Models

• Electron Cloud Bohrs
  Model