1. How the elements found in the
universe were formed
NS 002- PHYSCIE
WEEK1
2.
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.
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
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.
Madaliang paglapad ng singularity na pinagmulan ng universe.
After 3 minutes, HYDROGEN AND HELIUM WAS FORMED.
After 3 minutes, HYDROGEN AND HELIUM was formed and also Lithium and beryllium.
a. Heavy elements were formed only billions of years after the formation of stars.
200 million years after BB nucleosynth., because of the force of gravities the clouds of gases and dust compressed until fusion begins.
STAGES LIFE CYCLE OF A STAR
Nebula
Protostar
Main sequence star
Hydrogen is the fuel that powers star
PROTON-PROTON CHAIN- magsasanib ang dalawang hydrogen na magpoproduce ng deuterium.
- 2 deuterium can produce helium 3.
2. CNO CYCLE- (para sa stars na mas Malaki pa sa average stars like sun) this is to produce helium
TRIPLE ALPHA PROCESS- process which 3 helium nuclei are converted into carbon
Heavy elements were formed only billions of years after the formation of stars.
Ang mga elements na mas mabigat sa iron at bakal ay pede din mabuo sa core ng stars, thru NEUTRON CAPTURE.
HOW ARE ELEMENTS HEAVIER THAN IRON ARE FORMED IN THE STAR’S CORE?
In supernova, neutron capture reaction takes place, leading to formation of heavy elements.
neutron capture, type of nuclear reaction in which a target nucleus absorbs a neutron (uncharged particle), then emits a discrete quantity of electromagnetic energy (gamma-ray photon).
Two processes of neutron capture may be distinguished: the r -process, rapid neutron capture; and the s -process, slow neutron capture.
S-PROCESS- Process of forming heavier than iron over long periods of time. (matagal dahil paisa isang neutron lang.)
R-PROCESS- has a faster rate of capturing neutrons before seed nucleus undergoes radioactive decay.
Ang mga elements na mas mabigat sa iron at bakal ay pede din mabuo sa core ng stars, thru NEUTRON CAPTURE.
HOW ARE ELEMENTS HEAVIER THAN IRON ARE FORMED IN THE STAR’S CORE?
Why do stars undergo different life stages?
Because there are different processes happens in the core of star.
O with 17 atomic mass and 8 atomic num.
Atomic number and atomic mass
O with 17 atomic mass and 8 atomic num.
Rutherford made another discovery of Oxygen by nitrogen 14 and an alpha particle(He).
Proton and electron
HYDROGEN-
1932- Chadwick discovers neutron.
- NEUTRON HAS 0 ATOMIC NUM WHILE 1 ATOMIC MASS
THE ELEMENT TECHNICIUM IS THE FIRST ARTIFICIAL ELEMENTS. 1937.
PROTON AND ELECTRON – NEUTRON
