2. X-Rays
Nuclear energy
Electricity
&
Radiations
Nuclear Weapon
Fighter Aircrafts
Nuclear energy
X-Rays
&
Radiations

3. • A nuclear weapon is an explosive device that derives its destructive
force from nuclear reactions, either fission or a combination of
fission and fusion
• A modern thermonuclear weapon weighing little more than 2,400
pounds (1,100 kg) can produce an explosive force comparable to the
detonation of more than 1.2 million tons (1.1 million tonnes) of
TNT. Thus, even a small nuclear device no larger than traditional
bombs can devastate an entire city by blast, fire and radiation.
Nuclear weapons are considered weapons of mass destruction,
and their use and control have been a major focus of international
relations policy since their debut.
• Only two nuclear weapons have been used in the course of warfare,
both by the United States near the end of World War II. On 6 August
1945, a uranium gun-type device code-named "Little Boy" was
detonated over the Japanese city of Hiroshima. Three days later, on
9 August, a plutonium implosion-type device code-named "Fat Man"
was exploded over Nagasaki, Japan. These two bombings resulted in
the deaths of approximately 200,000 Japanese people—mostly
civilians—from acute injuries sustained from the explosions.

9. • Fighters were developed in World War I to deny enemy aircraft
and dirigibles the ability to gather information
by reconnaissance. Early fighters were very small and lightly
armed by later standards, and most were biplanes built with a
wooden frame, covered with fabric, and limited to about
100 mph. As control of the airspace over armies became
increasingly important all of the major powers developed
fighters to support their military operations. Between the wars,
wood was largely replaced by steel tubing, which became
aluminum tubing, and finally aluminum stressed skin structures
began to predominate.
• By World War II, most fighters were all-metal monoplanes armed
with batteries of machine guns or cannons and some were
capable of speeds approaching 400 mph.
• Wings were made thinner and swept back to reduce trans-sonic
drag which requiring new manufacturing methods to obtain
sufficient strength. Skins were no longer sheet metal riveted to a
structure, but milled from large slabs of alloy

17. Greek’s Concept of
matter (460-370 B.C.)
Matter is
discontinuous. It is
made up of Particles
called Atoms. The
properties of the
atoms determine the
properties of Matter.

18. Democritus
&
Leucippus
• The story of the two Greeks Democritus and
Leucippus.
Democritus and Leucippus tear a piece of paper
into smaller pieces until they cannot tear it
anymore. And they call it atom.

19. Democritus
&
Leucippus
• Atomic hypothesis
 The theory of Democritus and Leucippus held that everything is
composed of "atoms", which are physically, but not
geometrically, indivisible; that between atoms lies empty space;
that atoms are indestructible; have always been, and always will
be, in motion; that there are an infinite number of atoms, and
kinds of atoms, which differ in shape, and size. Of the mass of
atoms, Democritus said "The more any indivisible exceeds, the
heavier it is." But his exact position on weight of atoms is
disputed

20. Democritus
&
Leucippus
• Is there an ultimate, indivisible unit of matter?
 In the 5th century BC, Leucippus and his
pupil Democritus proposed that all matter was
composed of small indivisible particles called atoms,
in order to reconcile two conflicting schools of
thought on the nature of reality. On one side
was Heraclitus, who believed that the nature of all
existence is change. On the other side
was Parmenides, who believed instead that all
change is illusion.

21. Democritus
&
Leucippus
• With the work of Leucippus and Democritus
ancient Greek philosophy reaches its zenith
when the initial question of Thales after the true
nature of matter culminated 180 years later in
the subtle concept of atoms, which bears an
amazing resemblance to the twentieth century's
view of chemistry.

22. Democritus
&
Leucippus
• The atomistic theory began as an endeavor to overcome the
odd logical consequences of the Eleatic school. Leucippus and
Democritus did not accept the Eleatic hypothesis that
"everything is one" and that change and motion is an illusion.
Parmenides had said the void is a fiction, because saying the
void exists would mean to say there is something that is
nothing, which he thought is a contradiction in itself, but he was
deceived by thinking of "being" in the sense of "material being".
Thinking of the void as real would have overthrown
Parmenides' theory, because allowing the void to exist as
"space bereft of body" (Aristotle) with adjoining plenums implies
the opposite of classical monism.

23. Dalton’s Atomic Theory
(1804)
Atoms are indivisible
& indestructible. They
do not change during
chemical reaction.
Atoms of given
element have exactly
the same properties, but
atoms of different
elements have different
properties.

24. Dalton’s Atomic Theory
(1804)
Five main points of Dalton's atomic theory
• Elements are made of extremely small particles
called atoms.
• Atoms of a given element are identical in size, mass,
and other properties; atoms of different elements differ
in size, mass, and other properties.
• Atoms cannot be subdivided, created, or destroyed.
• Atoms of different elements combine in simple whole-
number ratios to form chemical compounds.
• In chemical reactions, atoms are combined, separated,
or rearranged.

25. Dalton’s Atomic Theory
(1804)
 Dalton proposed an additional "rule of greatest
simplicity" that created controversy, since it could not be
independently confirmed.
 When atoms combine in only one ratio, "..it must be
presumed to be a binary one, unless some cause
appear to the contrary".

26. Dalton’s Atomic Theory
(1804)
 This was merely an assumption, derived from faith in
the simplicity of nature. No evidence was then available
to scientists to deduce how many atoms of each
element combine to form compound molecules.
 In any case, Dalton's "rule of greatest simplicity" caused
him to assume that the formula for water was OH
and ammonia was NH, quite different from our modern
understanding.

27. Dalton’s Atomic Theory
(1804)
 Dalton's innovation was fully as important for the future
of the science as Antoine Laurent Lavoisier's oxygen-
based chemistry had been
 The law of conservation of mass
 The law of multiple proportions

30. Atoms

31. ATOM
• The name atom comes from
the Greek word (atomos, “indivisible”)
from ἀ- (a-, “not”) and (temnō, “I
cut”), which means uncuttable, or
indivisible, something that cannot be
divided further.

32. ATOM
• The atom is a basic unit of matter that
consists of a dense central nucleus
surrounded by a cloud of negatively
charged electrons.
• A group of atoms can remain bound to
each other, forming a molecule

33. ATOM
• The concept of an atom as an
indivisible component of matter was
first proposed by
early Indian and Greek philosophers. In
the 17th and 18th
centuries, chemists provided a physical
basis for this idea by showing that
certain substances could not be further
broken down by chemical methods.

34. ATOM
• The Development of the Atomic theory
began with intuitive thought, when
early Greek philosophers pondered of
the nature of matter.
• It took centuries to develop a complete
picture of the pattern.

35. ATOM
• During the late 19th and early 20th
centuries, physicists discovered
subatomic components and structure
inside the atom, thereby
demonstrating that the 'atom' was
divisible. The principles of quantum
mechanics were used to
successfully model the atom.

36. ATOM
• Atoms are minuscule objects with
proportionately tiny masses. Atoms can
only be observed individually using
special instruments such as
the scanning tunneling microscope.
Over 99.94% of an atom's mass is
concentrated in the nucleus, with
protons and neutrons having roughly
equal mass.

37. Cathode ray
experiments
(1879-1897)
Cathode Rays are
made up of Negative
particles called
Electrons.
Electrons(─) are
present in all kinds of
matter.
Protons are
positive particles
emanating from
behind the cathode

38. Thomson’s Plum
Pudding Model
(1891)
An atom is a
positive ball of
electricity with
negative electrons
embedded.

39. Albert Einstein Photon
Theory of Light
(1905)
Light wave carries
energy equal to h v,
consist of quanta or
corpuscles called
photon.

40. Rutherford’s Gold Foil
Experiment
(1908-09)
The atom is mostly
empty space. Its mass is
concentrated in the
nucleus. (Nuclear Model)
The Protons and
neutrons are particles
inside the nucleus.

41. Niels Bohr’s Atomic
Model
(1913)
The atom is like
solar system. Its
mass is concentrated
in the nucleus in
circular orbits.
Each electron has
discrete amount of
energy and does not
lose any energy.

42. Moseley’s X ray
experiments
(1913)
All atoms of one
element have the same
or fixed number of
protons.
The number of protons
or atomic number is what
identifies given element.

43. Moseley’s X ray
experiments
(1913)
All atoms of one
element have the same
or fixed number of
protons.
The number of protons
or atomic number is what
identifies given element.

44. Moseley’s X ray
experiments
(1913)
All atoms of one
element have the same
or fixed number of
protons.
The number of protons
or atomic number is what
identifies given element.

45. De Broglie’s
Particle-wave concept
of Electron(1924)
The electron has both
particle and wave
properties