1) There were two main phases of element formation in the universe: primordial nucleosynthesis during the Big Bang formed light elements like hydrogen, helium, lithium and beryllium. Stellar nucleosynthesis inside stars formed heavier elements through nuclear fusion. 2) During stellar nucleosynthesis, the high densities and temperatures inside stars allowed for nuclear fusion reactions to form heavier elements up to iron. Elements heavier than iron could only form during supernovae explosions. 3) Supernovae explosions were massive stellar explosions that created conditions for neutron capture reactions to occur, synthesizing elements heavier than iron.

1. How the elements found in the
universe were formed
NS 002- PHYSCIE
WEEK1

3. Formation of Light and Heavy Elements
The origin of all the naturally occurring
elements fall into two phases:
1. Big Bang or
Primordial
Nucleosynthesis
2. Stellar
Nucleosynthesis
—the origin of
the “light”
elements
— the origin and
production of the “heavy”
elements.

4. LIGHT ELEMENTS
These elements
were present
during the initial
formation of the
universe.

5. Nucleosynthesis
Process that
creates new
atomic nucleus
from pre-
existing
nucleons,
which is proton
neutrons.

6. What causes the neutrons and protons to
combine and form certain species of
atomic nuclei in a process called nuclear
fusion?
extremely high energy and
temperature of the universe
PROTONS NEUTRONS

7. Through Nuclear Fusion:
the light elements -
Hydrogen (H),
Helium (He), and
small amounts of
lithium (Li) and
beryllium (Be) were
formed.
A form of an element
that has the same
atomic number of
the original element
but with different
atomic mass or
mass number.
ISOTOPES

8. ISOTOPES

9. Origin of Heavier Elements
The density inside a star
is great enough to sustain
fusion for extended time
periods required to
synthesize heavy
elements.

10. STELLAR
NUCLEOSYNTHESIS
There are many nuclear
synthetic pathways or
nuclear fusions to
produce heavy
elements:
1. Proton-proton
fusion
2. Carbon-Nitrogen-
oxygen cycle
3. Triple alpha
The formation of
heavy elements
by fusion of lighter
nuclei in the
interior of stars

11. Origin of Heavier Elements
Layers near core of stars
have very high
temperatures enough to
nucleosynthesize heavy
elements such as silicon
and iron.

12. It cannot be formed through
fusion as tremendous
amounts of energy are
needed for the reaction to
occur.
Do you think elements heavier than Iron can
be formed through fusion?

13. In a neutron capture
reaction, heavy
elements are
created by addition
of more neutrons
to existing nuclei
instead of fusion
of light nuclei.
Neutron capture reaction

14. Do you think elements heavier than Iron can
be formed through fusion?
Heavy elements are
formed in a
supernova, a
massive explosion of
a star.

15. is the explosive death of a star.
Supernova

16. The Concept of Atomic Number that Led to the
Synthesis of New Elements in the Laboratory
ANATOMY OF A
NUCLIDE

17. NUCLEAR EQUATION:
reactants products
Alpha particles - He

18. NUCLEAR
TRANSMUTATION:
TRIVIA!
TECHNICIUM is the first artificial element

19. 02
THANK YOU!
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