Formation of heavier elements

1. Formation of
Heavier Elements
Physical Science
Prepared By: Francess Johanna F. Dela Fuente

4. BIG BANG MODELS
• Is the cosmological models based on general relativity – tell
us that the early universe was extremely hot and dense.
• At the earliest stages that can be modeled using current
physical theories, the universe was filled with radiation and
elementary particles – a hot plasma in which energy was
distributed evenly.

5. Big Bang Nucleosynthesis
• As the universe cools, the matter content changes – new
particles are formed out of the preexisting ones, such as
protons and neutrons forming out of quarks.
• From about one second to a few minutes cosmic time, when
the temperature has fallen below 10 billion Kelvin, the
conditions are just right for protons and neutrons to combine
and form certain species of atomic nuclei.

6. Life Cycle of a Star
• Nucleosynthesis is the process by which atoms of lighter chemical
elements fuse together, creating atoms of heavier elements.
• Atoms are comprised of three elementary particles - protons and neutrons
bound into a dense nucleus and electrons surrounding that nucleus.
• In the fusion process, light nuclei collide, recombine their protons and
neutrons into heavier nuclei, and release energy. This process requires
tremendous amounts of heat and energy; as such this fusion can only
happen in extreme environments.

7. QUESTION
WHAT IS THE NEAREST
STAR TO PLANET EARTH?

8. Life Cycle of a Star
• Stars populate the universe with elements through
their “lifecycle”—an ongoing process of
formation, burning fuel, and dispersal of
material when all the fuel is used up.

9. Life Cycle of a Star
• All stars form in nebulae, which are huge clouds of gas
and dust.
• Though they shine for many thousands, and even
millions of years, stars do not last forever.
• The changes that occur in a star over time and the final
stage of its life depend on a star's size.

10. Life Cycle of a Star
• Main sequence: Nuclear reactions at the centre (or core) of
a star provides energy which makes it shine brightly.
• The exact lifetime of a star depends very much on its size.
Very massive stars use up their fuel quickly. This means they
may only last a few hundred thousand years. Smaller stars use
up fuel more slowly so will shine for several billion years.

11. Life Cycle of a Star
• Eventually, the hydrogen which powers the
nuclear reactions inside a star begins to run out.
The star then enters the final phases of its lifetime.
All stars will expand, cool and change color to
become a red giant.

12. Life Cycle of a Star
• A massive star experiences a much more energetic and violent end.
It explodes as a supernova. This scatters materials from inside the
star across space to recombine as future stars, planets, and asteroids,
or even eventually life like us
• This material can collect in nebulae and form the next generation of
stars. After the dust clears, a very dense neutron star is left behind.
These spin rapidly and can give off streams of radiation, known as
pulsars.

13. Life Cycle of a Star
• If the remnant is more than three times as massive as
the Sun, gravity overwhelms the neutrons and the star
collapses completely into a black hole—so-called
because the matter within is so compressed and the pull
of gravity is so intense that even light is drawn in and
not reflected, so that area is “black” or unobservable.

14. QUESTION
WHAT IS MORE LIKELY
TO HAPPEN TO OUR SUN
AT ITS FINAL PHASE?

15. Formation of Heavier Elements
• A supernova generates such an unbelievable burst of energy.
In this brief moment, dozens of elements heavier than iron
can also be synthesized such as Nickel, Copper, Zinc,
Silver, and Gold.
• Any element with an atomic number greater than twenty-
six is made either in a supernova or a rare event like a
collision of a two-neutron star or a neutron star with a black
hole.

16. Proton-proton chain reaction
• A proton–proton chain reaction is one of the ways
by which stars fuse hydrogen into helium. It is the
reaction that dominates in stars the size of the Sun
or average-sized stars, where they get their energy
and convert Hydrogen into Helium

17. Proton-proton chain reaction
• Stars with a mass of about 1.5 solar masses or
more produce most of their energy by a different
form of hydrogen fusion, the CNO cycle.
• CNO stands for Carbon, Nitrogen, and Oxygen
as nuclei of these elements are involved in the
process.

19. TRIPLE ALPHA PROCESS
• The triple alpha process is a nuclear fusion process where three helium
nuclei are combined to form a carbon-12 nucleus (C-12). The C-12 nucleus
can sometimes capture an additional He-4 nucleus to produce an oxygen-16
nucleus (O-16).

20. Proton-proton chain and CNO cycle
• Proton-proton chain and CNO cycle cause He-4
nuclei to accumulate in the core of main-sequence
stars.
• When a main-sequence star evolves into its next
stage (e.g., red giant), the core temperature of the
star becomes sufficient for the triple-alpha process
to take place.

21. ALPHA LADDER PROCESS
• Stars accumulate more mass and continue to grow
into red super giants.
• Alpha particle fusion happens at its core and
creates heavier elements until Iron (Fe). This is
called the Alpha ladder process.

22. How do elements heavier than Iron form?
• In the growing ball of gas, strontium was found to
absorb light at wavelengths between 350 and 850
nanometers, according to computer simulations. They
noticed dips in the spectra at those wavelengths when
they reexamined the X-shooter spectra. The end
outcome was Strontium with a mass of five Earth
masses.

23. SLOW PROCESS/S-PROCESS
• In the creation of heavier elements, neutron
capture can occur slowly or quickly.
• When radioactive decay occurs more quickly than
neutron capture, the S-process, also known as the
slow process, happens, which raises the proton by
one.

24. SLOW PROCESS/S-PROCESS

25. RAPID NEUTRON CAPTURE/R-
PROCESS
• It refers to a higher rate of neutron capture before
radioactive decay, which leads to more neutrons
combining at the nucleus.
• Elements heavier than Iron originate during
supernova nucleosynthesis, which takes place in
this process.

26. RAPID NEUTRON CAPTURE/R-
PROCESS

27. SUMMARY
• Neutrons, protons, and electrons are the three
minuscule components that make up an element.
• The first elements to exist are Hydrogen and
Helium. It was an elementary particle at the
beginning of the Big Bang.
• During the period of the proton-proton chain
reaction, during which protons fused into helium,
the universe expanded and cooled.

28. SUMMARY
• The Universe expands right through this potential,
and the density and temperature quickly fall too
low to support the synthesis of any more elements.
Red giant cores get beyond this through the Triple-
Alpha process.

29. Synthesis of New
Elements

30. Dmitri
Mendeleev
• A Russian chemist,
who devised the
Periodic Table of
Elements — a
comprehensive system
for classifying
chemical elements.

31. Henry Moseley
• An English physicist, (1913) who used X-
rays to measure the wavelengths of
elements and correlated these
measurements to their atomic numbers.
• He then rearranged the elements in the
periodic table on the basis of atomic
numbers. This helped explain disparities in
earlier versions that had used atomic
masses.

32. Discovery of Nuclear Transmutation
• In 1919, Ernest Rutherford successfully carried out a nuclear transmutation
reaction — a reaction involving the transformation of one element or
isotope into another element.
• The first nuclide to be prepared by artificial means was an isotope of oxygen,
17O. It was made by Ernest Rutherford in 1919 by bombarding Nitrogen
atoms with alpha particles.

33. Ernest Rutherford

34. • James Chadwick discovered the neutron in 1932, as a previously
unknown neutral particle produced along with Carbon-12 by the
nuclear reaction between Beryllium-9 and Helium-4.
• The first element to be prepared that does not occur naturally on
the earth, Technetium, was created by bombardment of
Molybdenum by deuterons (heavy Hydrogen, H12), by Emilio
Segre and Carlo Perrier in 1937

35. The Discovery of the Missing
Elements
• In 1937, American physicist Ernest Lawrence
synthesized element with atomic number 43 using a
linear particle accelerator. He bombarded
molybdenum (Z=42) with fast-moving neutrons. The
newly synthesized element was named Technetium
(Tc) after the Greek word "technêtos" meaning
“artificial.” Tc was the first man-made element.

36. The Discovery of the Missing
Elements
• In 1940, Dale Corson, K. Mackenzie, and Emilio Segre discovered
element with atomic number 85. They bombarded atoms of
Bismuth (Z=83) with fastmoving alpha particles in a cyclotron. A
cyclotron is a particle accelerator that uses alternating electric field
to accelerate particles that move in a spiral path in the presence of
a magnetic field. Element-85 was named Astatine from the Greek
word “astatos” meaning unstable.

37. The Transuranic Elements
• Transuranic elements are chemical elements with
atomic numbers greater than 92, which means they
have more protons in their nuclei than uranium (atomic
number 92). These elements are all synthetic and do not
occur naturally in significant quantities on Earth.
•

38. The Superheavy Elements
Superheavy elements are those with atomic numbers
significantly higher than those found in the periodic table of
naturally occurring elements. They are highly unstable and
are typically synthesized in laboratories through nuclear
reactions. Here is a list of some superheavy elements along
with their atomic numbers:

39. The Superheavy Elements
Nihonium (Nh) - Atomic Number 113
Flerovium (Fl) - Atomic Number 114
Moscovium (Mc) - Atomic Number 115
Livermorium (Lv) - Atomic Number 116
Tennessine (Ts) - Atomic Number 117
Oganesson (Og) - Atomic Number 118

40. PERFORMANCE TASK
• Create an output that discusses the origin of one of the man-made
elements. In your output, you must:
• discuss the element’s basic characteristics
• give a brief timeline leading up to the element’s discovery
• You may present your research in the form of a poster, PowerPoint,
a report or essay, video, or infographic.