Fundamentals of Chemistry
Chemistry is the science that studies the composition and structure of matter and the changes it undergoes. Because everything in the universe is composed of matter, chemistry is the study of our material world. The chemical touches our lives and influences our activities in many ways that are often called the nuclear science. We chemistry practice all the time in our daily activities, i.e., the act of cooking, washing, taking medicine, fertilize the lawn, paint the house, or light a match, for example, are directly related to this science. In all these activities, substances interact and chemical changes occur. In our body when we breathe, walk and suffer food digestion, chemical reactions occur regularly. The environmental problems we experience and we deal today, as the disposal of domestic and industrial wastewater, acid rain, the greenhouse effect, photochemical smog, among many others, are all primarily chemical problems. Many goods are now made of polymers and ceramics instead of wood and metal thanks to our ability to produce materials with properties not found in nature. However, chemistry is essential in the current revolution in molecular biology, which is exploring the details of how life is genetically controlled, that is, no one today can understand the modern world without a basic knowledge of chemistry.
Transcript
00:08Why to study chemistry?
00:11Chemistry is the science
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undefined:undefined
undefined:undefinedstudy of our material world.
00:25The chemical touches our lives
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undefined:undefinedwashing, taking medicine,
00:41fertilize the lawn, paint the
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undefined:undefinedwalk and suffer food
00:57digestion, chemical
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undefined:undefinedphotochemical smog, among
01:13many others, are all
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undefined:undefinedthe current revolution in molecular
01:31biology, which is exploring the details
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undefined:undefined
undefined:undefined
undefined:undefined
undefined:undefinedreal word, from the Latin.
01:56In Latin, it means matter "what
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undefined:undefinedto study how matter is organized.
02:12The first manifestation
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undefined:undefined(now southeastern Turkey).
02:26It is impossible to have the
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undefined:undefinedfrom its very beginning, this
02:40new way of thinking contained
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undefined:undefinedsubsequent scientific thought.
02:56Tales asked the questions:
02:58"Why do things happen as they do?"
03:00And "What the world is
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undefined:undefinedunderlying unity to the world's diversity.
03:16But perhaps the most
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undefined:undefinedcontemplate and speculate" - testable.
03:31We know today that all
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undefined:undefinedthe atom can not be directly
03:46visualized, and then imagined
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undefined:undefinedaccepted as satisfactorily
04:00explain the phenomena
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undefined:undefinedone possibility envisioned
04:14by the human mind, always
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undefined:undefinedcomposed of tiny bits of
04:31matter has come up with
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undefined:undefinedform, position, and arrangement.
04:49All matter is made of indivisible
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undefined:undefinedDalton established changes
05:07in the atomic theory, which
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undefined:undefinedof Democritus, although correct,
05:24was philosophical as it did not
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undefined:undefinedwhich are called atoms.
05:412 ** - All atoms of the same
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undefined:undefinedformed when atoms combine
05:58in a constant and
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undefined:undefinedlater, changes the second assumption
06:17since isotopes are atoms of the same
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undefined:undefinedof one of the symbologies.
06:34The use of abstract symbols ended
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undefined:undefinedtime to change things he changed.
06:58Given that the old symbols were
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undefined:undefinedname of each elementary substance.
07:14The electron discovery
07:16In the nineteenth century, the works
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undefined:undefinedso-called cathode ray tube, i.e. a glass
07:39bulb connected to a vacuum pump, which
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undefined:undefinedabout one-tenth of ambient pressure,
07:54it is observed that the gas between
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undefined:undefineddisappears, leaving
08:07only a light spot behind
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undefined:undefinedthe atomic model of Thomson, who
08:23has used the electron to update
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undefined:undefinedbe distributed in the atom?".
08:37Thomson suggested that the total
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undefined:undefinedcompact, uniform mass.
08:51In this mass surface would be
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undefined:undefineddivisibility of the atom, but the atom
09:11was regarded as a positively charged
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undefined:undefinedexperience, which will be described below.
09:30The atom of Rutherford
09:33The second and third major innovation came
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undefined:undefinedand subsequently a dynamic model.
09:52To develop its atomic model
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undefined:undefinedelement) on a thin golden plate,
10:08to see whether these
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undefined:undefinedthe atoms were massive,
10:20using, for this, α particles, which have a
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undefined:undefinedbe gold, may be another metal.
10:39However, gold has been
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undefined:undefinedcan pass through the
10:51gold plate without
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undefined:undefinedpass through the blade, but
11:04suffering an unyielding
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undefined:undefinednot penetrate the leaf and
11:19return to the same side from
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undefined:undefinedpreviously proposed by Thomson as a compact
11:34mass of positive charges distributed
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undefined:undefinedthe atom is in a small central
11:54region (the core) having positive
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undefined:undefinedaround the nucleus (in the electron).
12:15Although sophisticated and accessible,
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undefined:undefinedof Rutherford, electrons
12:30could orbit the nucleus
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undefined:undefined(which deals with
12:41the movement of electrons)
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undefined:undefinedtend to spiral into the nucleus.
12:56It means that atoms would be unstable,
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undefined:undefinedof these comments
13:11were regarding the behavior
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undefined:undefinedthe radiation emitted by solid
13:23which is spread evenly across
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undefined:undefinedbe at any distance from the nucleus,
13:38but confined to discrete the same
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undefined:undefinedthis mathematical model and the succeeding,
14:02the full sophisticated
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undefined:undefinedof people who understand.
14:16The atomic theory of Bohr was
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undefined:undefinedof Rutherford with three postulates.
14:321- The electrons revolve around
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undefined:undefinedenergy to an orbital of lower energy.
14:53ΔE = h.f, the energy emitted
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undefined:undefinedinteger multiple of h / 2π.
15:10Thus, the third postulate tells us
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undefined:undefinedwill be presented later)
15:28n = 1,2,3,4,5,6, .... ∞
15:37In the atomic model of Bohr, we note that:
15:411. The atomic model of Bohr explains
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undefined:undefinedonly one electron).
15:573. Does not explain the narrow spectrum.
16:014. Calculations rays and
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undefined:undefinedpulses, packets, or quanta.
16:237. Ray discontinuous in heels or wrists.
16:28Application of the Bohr model
16:31• Flame test;
16:32• Fireworks;
16:34• Bright and lamps (neon
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undefined:undefinedif the orbits were circular.
17:04Then Sommerfeld suggested that the
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undefined:undefinedthe azimuthal quantum
17:20number, which defines the
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undefined:undefined0 and elliptical).
17:39For any principal quantum number n,
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undefined:undefinedfrom other scientists, namely:
17:57• Louis Victor de Broglie (1925):
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undefined:undefinedscientists Davisson and Germer.
18:16• Werner Heisenberg (1927):
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undefined:undefinedpossible to establish defined orbits.
18:34This statement received
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undefined:undefinedthat allow determining the energy and
18:50regions of the probability of finding the
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undefined:undefinedmodel of the Rutherford-Bohr atom
19:08and appeared a new atomic model, the
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undefined:undefinedvarious features atoms.
19:31In an electrically
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undefined:undefinedto 26 mass number (A): The sum
19:57of the number of protons and
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undefined:undefinedthe difference between
20:20the mass number (A) and
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undefined:undefinedthan negative charges (electrons).
20:43It occurs because the atom lost electrons.
20:46The total number of
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undefined:undefinedatom electrons gained.
21:12The total gains electrons are equal to
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undefined:undefinednegative, determines the valence.
21:37The cations and anions can be
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undefined:undefinedatomic mass medium or medium
22:01atomic weight) is the average
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undefined:undefinedto represent as amu).
22:17• Molecular weight: it
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(1.0 x 2) +
:undefined(16 x 1) = 18u
22:34• Mol: is the unit of measurement
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undefined:undefinedhas 6,023 x 1023 molecules of this gas.
23:00One mole atoms of any element weigh
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Molar mass is the mass
:undefinedof moles of atoms of any element.
23:26The molar mass of an element
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numerical constant
:undefinedapplied both in chemistry and in physics.
23:44The formal definition of the Avogadro
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Why always Carbon-12?
:undefined
undefined:undefinedchosen as a reference substance
24:12because its atomic mass can
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undefined:undefinedpressure and temperature.
24:29CNTP5 in the molar volume equals 22.71
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undefined:undefinedbut have different mass numbers (A).
24:59• Isobars are atoms
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undefined:undefineddifferent atomic and mass
25:13numbers, but with the
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undefined:undefinedquantity is a number which
25:32expresses a quantity compared
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undefined:undefinedpreviously known, a standard mass.
25:50For this determination, it
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undefined:undefinedof a portion expressed
26:05matter how much space
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undefined:undefined
undefined:undefineddecimeter (dm³) per liter (L), cubic
26:26centimeter (cc), milliliter
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undefined:undefinedused in the chemical liter (L).
26:45General Properties of Matter
26:49Are the properties of
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undefined:undefinedthe extension of a body.
27:03Your body, for example, has the
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undefined:undefineda body, the harder it
27:18is to change its movement
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the
:undefinedproperty of matter that is to
27:36have low volume when subjected
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property
:undefinedthat the matter has
27:51to be divided into smaller
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When burned:undefinedinto gasses, smoke, and ash.
28:13Specific properties of matter
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the ability
:undefinedof a substance to reflect
28:31light is what determines
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undefined:undefined
:undefinedperceived by touch;
28:59• Hardness: Resistance is
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undefined:undefinedanother leaving a groove.
29:12To determine the hardness of
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undefined:undefinedmaterials such as glass.
29:30• Malleability: property that
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copper:undefined
found through
:undefinedreason (division) between
29:55the mass of a substance and
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undefined:undefinedpieces of lead, all sink.
30:08Some people try to explain this by
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undefined:undefined
undefined:undefinedmatter the dough: pieces of
30:25cork floating in the water
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undefined:undefineddividing its mass by its volume.
30:43State of matter
30:45All matter is made up of small particles
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undefined:undefined
:undefinedsolid, liquid and gaseous.
31:02The stones, ice, and wood are
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undefined:undefinedof aggregation has its
31:20characteristics - such
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undefined:undefinedstate, undergoes changes
31:33in its macroscopic
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undefined:undefined
undefined:undefinedcomes from the Latin corpu.
31:49A body is a limited portion of matter.
31:52For example, the noun designates
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undefined:undefined461
undefined:undefined
undefined:undefinedphysical space or not
32:09containing matter and that
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undefined:undefined
undefined:undefinedis the rest of the universe.
32:26Molecules
32:28From Latin molecule, it
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undefined:undefinedor a chemical compound
32:41that can exist in the free
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undefined:undefinedbut gaseous hydrogen and gaseous oxygen.
33:01Types of transformations
33:03By analyzing the changes
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undefined:undefinedas folding and unfolding a sheet of paper.
33:20The other type of transformation occurs
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undefined:undefinedor both receive the phenomenon name.
33:38The phenomena can be divided into Chemical
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undefined:undefinedDollar is a chemical phenomenon.
33:56• Physical hazards are those
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undefined:undefined
undefined:undefineda physical phenomenon.
34:10Chemical elements
34:12Everything that is
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undefined:undefinedi.e. are pure substances existing in nature.
34:29Silver, mercury and sulfur
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undefined:undefined501
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undefined:undefinedparticle accelerators.
34:47Each chemical element is represented
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undefined:undefined505
undefined:undefined
undefined:undefinedthat is found in nature,
35:01some characteristic of the
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undefined:undefined
undefined:undefined
undefined:undefinedspectrum analysis of
35:20sunlight, is the sun god
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undefined:undefinedtheir representation.
35:35The nomenclature most widely accepted
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undefined:undefined
undefined:undefinedthey form thousands of different chemicals!
36:00How is this possible?
36:02Only because the atoms of chemical
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undefined:undefinedchapter chemical bonds).
36:18Each group forms a chemical.
36:21The graphical representation of the chemical
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undefined:undefined
undefined:undefinedformula of water is H₂O.
36:39So when we say that the
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undefined:undefined
undefined:undefinedatom of element oxygen.
36:52The most widely used
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undefined:undefinedare interconnected.
37:03The other types are the gross
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