Instructions:

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EXPLORING ENERGY AND MATTER
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Properties of Matter

• The universe and everything in it is composed of
  stuff called matter,
• ANYTHING that has mass and takes up space is
  classified as Matter.
• So what is mass?
• Mass is a measurement that reflects the amount of
  matter in the object
• Its very similar to weight

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Properties of Matter

• Its easy to see some of the things that have
  mass and take up space -- like your textbooks,
  but what about air?
• When you inflate a balloon, the latex-rubber
  expands to make room for the air
• Thats space
• The balloon gets heavier
• Thats mass
• Therefore, air is by definition matter

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• So if stuff we can see is matter and stuff we
  cant see is matter, than is everything matter?
• Not quite everything, for instance, heat isnt,
  nor light, nor radio waves, nor magnetic fields
• So, if mass and weight are pretty much the same
  what is the difference?
• weight is a measure of the amount of matter
  taking into account the effect
  of Earths gravitational
  pull on that matter

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• Gravitys pull is not exactly the same everywhere
  on earth and actually becomes less as you move
  away from the earths surface
• You may not notice a difference in the weight of
  a pound of vegetables from one place to another,
  but subtle differences do exist
• Gravity is different, but the amount of matter in
  the material doesnt change from place to place
• So we will use mass as our measure of the weight

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• Much of matter and its behavior is macroscopic
• You can see it with the naked eye
• Whats fascinating is that all of the tremendous
  variety of stuff around you can be broken down
  into no more than 100 different types of matter
• These are called, elements
• Elements are made up of particles
  called atoms
• Atoms are so tiny that they cannot be seen even
  with optical microscopes
• Thus atoms are sub-microscopic

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• Atoms are so small that 100 million million
  million atoms could fit onto the period at the
  end of this sentence.
• The structure, composition, and behavior of all
  matter can be explained on a sub-microscopic
  level
• All that we observe about matter depends on
  atoms and the changes they undergo
• Chemistry seeks to explain the
  submicroscopic events that lead to
  macroscopic observations

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• Matter that has a uniform and unchanging
  composition is called a substance, AKA pure
  substance
• Table salt is a pure substance
• Water is a pure substance
• Seawater is not a pure substance because samples
  taken from different locations will probably have
  differing compositions
• contains differing amounts of
  water, salts, and other dissolved
  substances
• Seawater is a mixture

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• A mixture is blend of pure substances
• When mixtures are separated the result is
  generally one or more pure substances
• A pure substance has a fixed composition and
  differs from a mixture in the following ways

1. Every sample of a given pure substance has
   exactly the same characteristic properties
2. Every sample of a given pure substance has
   exactly the same composition

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Combinations of Matter

• Pure substances are either compounds or elements
• A compound can be decomposed, or broken down into
  two or more simpler components by a chemical
  change
• An element can not be broken down into anything
  simpler, without changing its identity

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Basic Building Blocks of Matter

• Compounds and elements are composed of the same
  basic building block - atoms
• Elements are composed of a single type of atom
• Compounds are a combination of 1 or more atoms
  simplest form it is called a molecule
• An atom is the smallest unit of an element that
  maintains the properties of that element.
• An element is a pure substance made of only one
  kind of atom.

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Basic Building Blocks of Matter

• A compound is a substance that is made from the
  atoms of 2 or more elements that are chemically
  attached.
• Many compounds consist of molecules.
• For example water
• Water is an example of a
  compound composed of a
  combination of
  Hydrogen and Oxygen

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Basic Building Blocks of Matter

• The atoms of Hydrogen and Oxygen are chemically
  bonded to form a water molecule
• A molecule can be thought of as the smallest unit
  of an element or compound that retains all of the
  properties of that element or compound.
• They are considered pure substances if the sample
  contains only a collection of identical molecules

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Combinations of Matter

• One of the most common combinations of matter is
  the mixture obvious mixtures are
• Chicken noodle soup
• Sea water
• Koolaid
• Other mixtures may be much harder to recognize.
• Air is a mixture of gases, but its components
  cannot be distinguished by the eye.
• A mixture is a blend of 2 or
  more substances

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Combinations of Matter

• One important characteristic of mixtures is that
  their compositions can vary
• The composition of air in a forest may differ
  from that in an industrial city, particularly in
  the amounts of pollutants
• Blood is a mixture of water, various
  chemicals, and cells, which varies
  somewhat in composition from one
  individual to another and, from time
  to time, in a given individual

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Combinations of Matter

• There are 2 classifications for mixtures
• Heterogeneous mixture is one that is not uniform
  in composition
• If you were to sample one portion of such a
  mixture, its composition would be different from
  that of another portion
• Homogeneous mixture is one that has a completely
  uniform composition
• Its components are evenly distributed throughout
  the sample

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Combinations of Matter

• Homogeneous mixtures are so important in
  chemistry that chemists give them a special name
• Solutions - which may be gases, liquids, or
  solids
• If you were to take a sample from any portion of
  a solution of sugar in water, you would find that
  it has the same composition as any other portion

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Types of Solution Systems Types of Solution Systems
System Example
Gas-gas Air is primarily a mixture of nitrogen, oxygen, and argon gases.
Gas-liquid Carbonated beverages contain carbon dioxide gas in solution.
Liquid-gas Moist air contains water droplets in air (which is a mixture of gases).
Liquid-liquid Vinegar contains acetic acid in water.
Solid-liquid Sweetened powder drink contains sugar and other solid ingredients in water.
Solid-solid Steel is an alloy of iron containing carbon.
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Separating Mixtures

• Heterogeneous mixtures can be separated into
  their components by simple physical methods.
• You might use a fork to separate taco filling
  into meat, lettuce, cheese, and tomatoes
• Separating a mixture of sand and iron fillings
  might be done with a magnet
• You can use a filter to remove sawdust from water.

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Separating Mixtures

• Homogeneous mixtures require special methods of
  separation.
• Tap water is a homogeneous mixture of water plus
  other substances that are dissolved in it.
• To separate out the impurities from the water you
  might have use a technique called distillation.
• With distillation the liquid is boiled off and
  collected, while the dissolved impurity is left
  behind

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Separating Mixtures

• Another technique for separating a homogeneous
  mixture, is crystallization
• rock candy is made by crystallization
• Crystallization is a technique that results in
  the formation of pure solid particles of a
  substance from a solution containing
  the dissolved substance.
• Produces highly pure solids

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Separating Mixtures

• Another technique for separating a homogeneous
  mixture, is chromatography
• A technique that separates the components of a
  mixture (called the mobile phase) on the bases of
  the tendency of each to travel or be drawn across
  a surface of another material
  (stationary phase)

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Classification of Matter Chart
MATTER
physically
SUBSTANCE Definite composition (homogeneous)
MIXTURES Variable composition
separable
chemically
ELEMENT (Iron, sulfur, carbon, etc.)
COMPOUND (Water, iron Sulfide)
HOMO- GENEOUS (uniform throughout, also called a
solution)
HETERO- GENEOUS (non-uniform distinct particles)
separable
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Basic Building Blocks of Matter

• Elements are organized into groups based on
  similar chemical properties.
• This organization of elements is the periodic
  table

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Basic Building Blocks of Matter

• Each small square on the PT shows the name of one
  element and the letter symbol for the element
• For example the first square, at the upper left,
  represents element 1, hydrogen, which has the
  symbol H.

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Basic Building Blocks of Matter

• The vertical columns of the PT are called groups,
  or families
• Notice they are numbered 1-18 from left to right
• Each group contains elements with similar
  chemical properties
• Elements in group 2 are beryllium, magnesium,
  calcium, strontium, barium, and radium
• All of these elements are reactive metals that
  bond to similar elements to form compounds

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Basic Building Blocks of Matter

• The horizontal rows of elements are called
  periods.
• Physical and chemical properties change somewhat
  regularly across a period
• Elements that are close to each other in the same
  period tend to be more similar than elements that
  are farther apart
• The two sets of elements that are set apart from
  the others are called the lanthanide series and
  actinide series.

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Basic Building Blocks of Matter

• The PT is divided into two main sections metals
  and nonmetals.
• Metals are at the left and in the center of the
  table
• Nonmetals are at toward the right.

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Basic Building Blocks of Matter

• Some of the properties of metals may be familiar
  to you.
• For example, you can recognize metals by their
  shininess, or metallic luster.
• The most important characteristic property of
  metals is the ease with which they conduct heat
  and electricity
• A metal is an element that is a good
  conductor of heat and electricity

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Basic Building Blocks of Matter

• At room temperature, most metals are solids
• Most metals are malleable
• That is they can be hammered or rolled into thin
  sheets
• Metals are tend to be ductile
• They can be drawn into a fine wire
• Metals behave this way because they have high
  tensile strength
• The ability to resist breaking when pulled

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• Many nonmetals are gases at room temperature
• These include nitrogen, oxygen, fluorine,
  chlorine, etc.
• One nonmetal is a liquid
• Bromine
• The solid nonmetals include carbon, phosphorus,
  selenium, sulfur, and iodine
• These solids tend to be brittle rather than
  malleable and ductile
• A nonmetal is an element that is a poor conductor
  of heat and electricity

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• A stair-step line separates the metals from the
  nonmetals on the PT.
• Several of the elements in the vicinity of the
  line are often referred to as metalloids
• A metalloid is an element that has some
  characteristics of metals and some
  characteristics of nonmetals
• Metalloids tend to be semiconductors of
  electricity
• Ability to conduct electricity is intermediate
  between metals and nonmetals

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More About Pure Substances

• Substances are important much of your chemistry
  course will be focused on the processes by which
  substances are changed into different substances
• In order to distinguish one substance from
  another we examine its properties
• substances characteristics and behaviors
• We look for things like shape, color,
  weight, or some other physical
  characteristic

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Physical Properties of Matter

• A physical property is a characteristic that can
  be observed or measured without changing the
  samples composition
• Physical properties generally describe pure
  substances.
• The physical properties of pure substances are
  consistent, predictable, and unique
• They can be used to identify the
  substance

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• Density, color, odor, taste, hardness, melting
  point, and boiling point are common physical
  properties
• A phys prop of Sodium chloride is that it forms
  solid, white crystals at room temperature
• Each crystal has the same unique salty taste
• There are tables upon tables of physical data
  storing physical properties

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Physical Properties of Common Substances Physical Properties of Common Substances Physical Properties of Common Substances Physical Properties of Common Substances Physical Properties of Common Substances Physical Properties of Common Substances
substance Color State at 25?C Melting pt (?C) Boiling pt (?C) Density (g/ml)
Oxygen Color-less Gas -218 -183 .0014
Mercury Silver Liquid -39 357 13.5
Water Color-less Liquid 0 100 1.00
Sucrose White Solid 185 De-composes 1.59
Sodium chloride White Solid 801 1413 2.17
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• Furthermore, there are 2 types of physical
  properties
• Extensive properties, which are dependent on the
  amount of substance present
• For example, mass, which depends on the amount of
  substance there is
• Intensive properties, which are independent of
  the amount of the substance present
• Density of a substance is the same no matter how
  much substance is present

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• A substance is often identified by just its
  intensive properties
• In some cases, a single intensive property is
  unique enough for i.d.
• During the California gold rush, miners relied on
  golds characteristics density (19g/ml) to
  separate valuable gold-containing flakes from
  riverbed sand
• Appearance (extensive prop) isnt enough to
  determine if a sample is Gold it might be
  pyrite or fools gold

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Chemical Properties of Matter

• Some properties of a substance are not obvious
  unless the substance has changed composition
• The ability of a substance to combine with or
  change into, one or more other substances is
  called a chemical property
• The ability of iron to rust when combined with
  air is a chemical property of iron

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Chemical Properties of Matter

• Also the inability of a substance to change into
  another substance is a chemical property.
• When iron is placed in Nitrogen gas at room temp,
  no chemical change occurs
• Therefore, another chemical property of iron is
  that it is impervious to reaction with Nitrogen
  gas

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Observing Properties of Matter

• Every substance has its own unique set of
  physical and chemical properties
• Observations of properties may vary depending on
  the conditions of the immediate environment
• It is important to state the specific conditions
  in which observations are made because both
  chemical and physical properties depend on temp
  and pressure

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Physical Vs. Chemical Properties Physical Vs. Chemical Properties
PHYSICAL PROPERTIES A characteristic of a substance that can be observed or measured without changing composition.
PHYSICAL PROPERTIES Ex density, color, shape, hardness, melting boiling points
PHYSICAL PROPERTIES 2 kinds of phys properties Intensive and extensive
CHEMICAL PROPERTIES The ability of a substance to undergo chemical reactions and to form new substances
CHEMICAL PROPERTIES Ability to burn, to react, to decompose, etc.
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Changes in Matter

• A change in a substance that does not involve a
  change in the identity of the substance is called
  a physical change
• Physical changes include grinding, cutting,
  melting, and boiling a material
• These changes dont affect the identity of the
  substance
• If you boil water the steam is still composed of
  the same compound that makes up water

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Changes in Matter

• Melting and boiling are part of an important
  class of physical changes called changes of state
• Change of state is a physical change of a
  substance from one state of matter to another
• The 3 common states of matter are solid, liquid,
  and gas

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Changes in Matter

• Matter in the solid state has definite volume and
  definite shape.
• A piece of quartz or coal keeps its size and
  shape
• Regardless of what the container looks like
• The particles in a solid are packed
  together in relatively fixed positions
• They are held close together by strong
  attractive forces
• Vibrate about fixed points

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• Liquids have a definite volume, but take the
  shape of their containers.
• A given quantity of water takes up a definite
  amount of space, but the water takes the shape of
  the glass
• Particles are packed close together, but have
  more freedom to pass around each other
• The particles move more rapidly
  than those in a solid breaking
  free of some of the forces
  holding in place.

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• Gases have a neither a definite volume, nor a
  definite shape
• Gases expand to fill any size container and take
  the shape of the container.
• All gases have this characteristic because they
  are composed of particles that move very rapidly
  and are at great distances from one another
• At these great distances, the
  attractive forces between gas particles
  are much weaker than
  those in liquids and solids

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• An important fourth state of matter is plasma.
• A high temperature physical state of matter in
  which atoms lose their electrons
• Plasma is found on the sun

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• There are 3 basic changes of state
• Melting is the change from solid to liquid
• Boiling is a change of state from liquid to a
  gas.
• Freezing, the opposite of melting, is the change
  from a liquid to a solid.
• No change of state affects the identity of the
  substance
• When ice melts to liquid water or when liquid
  water boils to form water vapor, it is composed
  of the original substance in another form

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• To change matter from one state to another
  requires energy.
• Specifically kinetic energy
• The measure of that kinetic energy is called
  temperature
• Temperature is a measure of how fast the
  particles of a substance are vibrating.
• The faster the particles are vibrating the higher
  the temperature
• The slower the particles are vibrating
  the lower the temperature

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• As you add heat (energy) to a solid
• the particles that make up that substance vibrate
  with more energy and speed.
• as they increase in vibrational energy the
  particles begin to break apart and have enough
  energy to tumble over and around each other
• Melts to become a liquid

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• if energy continues to be added
• the particles vibrations are energetic enough to
  break all the bonds holding them in place.
• the particles have enough energy to spread out as
  far as the container will allow
• becomes a gas
• This works backwards as well
• Energy can be removed

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• The energy (temperature) of an object determines
  the direction of heat transfer.
• When 2 objects at different temps are in contact,
  heat moves from the object with a higher
  temperature to the object with a lower
  temperature.
• Particle collides with particle transferring
  energy the particle with more energy transfers
  its motion to the other particle
• So particle by particle the energy is
  transferred along the expanse of the object

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• We use a thermometer to measure the amount of
  kinetic energy in an object.
• Thermometers contain a pool of liquids that
  either expand when absorbing energy or contract
  when releasing energy
• Warm liquids take up more room than cool liquids
• Most objects expand when heated and contract when
  cooled
• An exception to this is water, which expands when
  cooled and contracts when heated

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• Several temp scales have been devised through the
  years.
• One common temperature scale is the Celsius
  scale.
• The celsius scale was derived by a Swedish
  astronomer Anders Celsius
• The scale itself is based on the freezing point
  of water and the boiling point of water.
• The numbers 0 was given to the freezing point
• And 100 was given to the boiling point.

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• The distance between those two points was divided
  into 100 equal increments or degrees
• Another temperature scale used in this class is
  the Kelvin scale.
• The scale was named for Lord Kelvin, a
  Scottish physicist and mathematician
• On the Kelvin scale the fp of water records at
  273K, while the bp of water records at 373K.
• Notice that as in the Celsius scale there is 100
  degrees difference between the freezing point and
  boiling point of water

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373 K
100C
WATER BOILS

• You can use this figure to compare the two
  temperature scales.
• Notice in particular the temperatures at 0 Kelvin

21C
294 K
ROOM TEMP
0C
273 K
WATER FREEZES
-173C
100 K
AIR LIQUIFIES
-273C
0 K
ABSOLUTE ZERO
ALL MOTION STIOPS
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• The zero point on the Kelvin scale is called
  absolute zero
• It is equal to 273C.
• At absolute zero particle motion stops lets
  check it out.
• 1 degree on the celsius scale is equal to 1
  kelvin on the Kelvin scale.
• Converting from one scale to the other is easy.
• You simply add or subtract 273.

K C 273
C K - 273
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Changes in Matter

• Physical properties can be observed without
  changing the identity of the substance, but
  chemical properties cannot.
• Again, a chemical property relates to a
  substances ability to undergo changes that
  transform it into different substances.
• Chemical properties are easiest to see when
  substances react to form new substances

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Changes in Matter

• After a chemical change, the original substances
  are no longer present.
• A different substance with different properties
  has been formed
• A change in which one or more substances are
  converted into different substances is called a
  chemical change or chemical reaction.
• The substances that react in a chemical change
  are called reactants.

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• The substances that are formed by the chemical
  change are called the products
• In the case of a campfire
• The carbon that makes up the wood reacts with
  oxygen are the reactants
• The carbon dioxide and the heat energy are the
  products
• The chemical change can be described as follows
• Carbon plus oxygen yields or forms carbon dioxide.

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Changes in Matter

• Chemical changes and reactions form products
  whose properties differ greatly from those of the
  reactants.
• However, the chemical changes do not affect the
  total amount of matter present before and after a
  reaction.
• The amount of matter, and therefore the total
  mass, remains the same.
• This is known as the law of conservation of
  matter or mass

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Changes in Matter

• During any chemical reaction, the total quantity
  of matter is unchanged.
• The mass of the products is equal to the mass of
  the reactants.
• Constant mass also holds for physical changes
• When 10 grams of ice melt, 10 grams of
  water are obtained
• Similar observations have been recorded for all
  chemical and physical changes studied

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Changes in Matter

• The Law of Conservation of Mass states that in
  any physical change or chemical reaction, mass is
  neither created nor destroyed
• So what does this mean?
• The amount of matter in the universe is constant.
• It simply changes from one form to another
  through chemical or physical processes
• It is eternal the wood in the pencil you are
  using has always been here.