3. Born on November 23, 1887
Died in August 10, 1915
Henry Gwyn Jeffrey Moseley
or Henry Moseley was a British
physicist who made significant
contributions to the field of
atomic physics.
4. He is best known for Moseley's law. A study of the
X – ray spectra that led him to propose the atomic
number. Moseley's work played a crucial role in
the development of the modern periodic table by
arranging the elements in order of increasing
atomic number, rather than atomic mass. Up to
this date, his work is very significant because the
elements are still arrange in terms of their atomic
number.
5. His discoveries helped to establish the concept of
atomic number as the fundamental property of
an element. Tragically, Moseley's promising career
was cut short when he was killed in action during
World War I at the age of 27. Despite his untimely
death, his work had a profound impact on the
field of atomic physics and laid the groundwork
for many future advancements in the
understanding of the atom.
7. Atomic Number refers to the number of protons found
in the nucleus of atom, which determines the chemical
properties on an element. The atomic number is
represented by the symbol “Z” and is typically listed
along with the element’s and name in the periodic
table.
9. The Atomic Number and Mass Number
The X-ray spectroscopy of Henry Moseley, a British physicist
played a significant development in determining the atomic
number of the elements. In his experiment, the different
beam of electrons bombarded with other elements
produced varying frequencies of x-ray spectral lines. He
measured and concluded that these frequencies revealed
by the elements in his worked were similar location in the
periodic table of elements.
10. Therefore, he assigned these frequencies as the
atomic number of each element. The atomic
number indicates the number of protons found in
the nucleus of each element. It also serves as the
identity of an atom.
11. Did you know?
Every atomic number of one element is naay 3 ka particles?
This particles is called as the Subatomic particles
Which is: Protons
Neutrons
Electrons
12. Therefore, he assigned these frequencies as the
atomic number of each element. The atomic
number indicates the number of protons found in
the nucleus of each element. It also serves as the
identity of an atom.
13. In a neutral atom, the number of protons is equal
to the number of electrons. Thus, atomic number
is equal to the number of electrons in a neutral
atom. For instance, aluminum has an atomic
number of 13, meaning each neutral atom of
aluminum has 13 protons and electrons.
14. In general, the acceptable representation of atomic number is this
symbol, capital “Z”. The total number of neutrons and protons in the
nucleus of an atom referred mass number. The mass number
represents by this symbol, capital “A”.
Where:
Atomic number (Z)= number of protons (p+) = number of electrons (e-)
Mass number (A)= number of protons (p+) + number of neutrons (n⁰)
= Atomic number (Z) + number of neutrons (n⁰)
Number of neutrons (n⁰) = Mass number (A) – number of protons (p+)
15. Note:
Protons are positive charge, Electrons are negative
charge, and Neutrons are neutral or no charge.
19. The Synthesis of New Elements
The understanding of atomic number also paved the way for
the synthesis of new elements. Synthesis of new elements
involves the creation of atoms with atomic numbers higher
than those found naturally on Earth. The scientists used a
particle accelerator to synthesize new synthetic elements. The
particle accelerator is a device used to speed up the
electrically charged atomic particles or subatomic particles by
using magnetic and electrical fields.
20. The cyclotron is a type of particle
accelerator developed by Ernest
Lawrence in 1930. It uses a
combination of electric and magnetic
fields to accelerate charged particles
in a spiral path. This technology was
crucial in advancing the study of
nuclear physics and led to the
discovery of many new isotopes. The
cyclotron also had important
applications in the medical field, as it
could be used to create radioactive
isotopes for medical imaging and
cancer treatment.
21. In 1930, the element 92, Uranium was the heaviest element
discovered at that time. The eagerness of scientists to study
and discover the behavior and characteristics of the
elements challenged them to create new elements. By the
year 1937, Ernest Lawrence used linear particle accelerator
in creating element 43 by bombarding the atoms of
molybdenum with atomic number 42 with fast moving
electrons. He named this element 43 as Technetium. The
first man-made element.
22. The first elements to be synthesized were created by Ernest Lawrence
and his colleagues in the early 1900s. They bombarded nitrogen gas
with alpha particles and discovered that the resulting nuclei contained
one additional proton, creating the first artificially created element.
23. In 1940, the element astatine with atomic number 85 is
synthesized by the collaboration of three great scientists, Emilio
Segre, Kenneth Mackenzie and Dale Corson by bombarding the
atoms of element bismuth with atomic number 83 using the
fast moving alpha particle. In the same year, Edwin McMillan
used particle accelerator to bombard uranium with neutrons
that led him to discover the element with atomic number 93.
He called it neptunium.
24. In the late 1940, the four scientists namely, Glenn Seaborg, Edwin
McMillan, Joseph Kennedy and Arthur Wahl synthesized element 94
by bombarding the uranium with deuterons in the cyclotron. The
cyclotron is a particle accelerator used in alternating electric field to
accelerate particles that move in a spiral path in the presence of a
magnetic field. The deuterons are particles made of a proton and a
neutron. They named the element 94 to plutonium.
25. In the periodic table of elements, elements with atomic
number higher than 92 are belong to the group or family of
transuranium elements. Since, elements neptunium and
plutonium have atomic number 93 and 94 respectively are
grouped in the family of transuranium elements. These
elements are unstable and radioactively decay into other
elements. The transuranium elements are created using
nuclear reactors or particle accelerators. The particle
accelerators are used to create new elements in the
laboratory. These elements are synthesized in the laboratory
and considered as synthetic elements.
26. The synthesis of new elements has led to new
discoveries and advancements in the field of nuclear
physics. It has also contributed to the development of
new technologies, such as medical imaging techniques
and nuclear energy. However, the synthesis of new
elements is still a challenging and complex process,
requiring advanced technology and expertise in nuclear
physics.
27. The conclusion of the Atomic number and Synthesis of new
elements is that the periodic table is a useful tool for
understanding the properties and behavior of elements, and
that the synthesis of new elements beyond atomic number
118 is extremely challenging due to the instability and short
half-lives of these superheavy elements. Lastly, the study of
the synthesis of new elements has led us to a better
understanding of nuclear physics and the limits of the nuclear
landscape.
