Formation of Elements: Key Terms

Formation of the Elements: Key Terms

• Nuclear reactions involve changes in the nuclei of atoms.
• Fusion is the process of joining two or more entities to form a single one.
• Fission is the action of dividing or splitting something into two or more parts.
• Isotopes are variants of a chemical element which have the same number of protons and electrons, but different number of neutrons.
• Atoms are the basic building blocks of matter.
• Protons are subatomic particles with a positive electric charge.
• Neutrons are subatomic particles with no electric charge.
• Electrons are subatomic particles with a negative electric charge.
• Nucleosynthesis is the process of creating new atomic nuclei.
• The Big Bang theory describes the early development of the universe.
• Stellar refers to stars.
• Supernova is a powerful and luminous stellar explosion.

Definition of Terms

• Nucleosynthesis is the creation of new atomic nuclei, focusing on the protons and neutrons at the center of atoms, and is the process by which elements are formed.
• Nuclear reactions are the processes involving the nuclei of atoms.
• Fusion is the process of joining two or more entities to create a single entity.
• Fission is the action of splitting something into two or more parts.
• Atomic number is the number of protons in the nucleus of an atom.
• Mass number is the total number of protons and neutrons in an atom's nucleus.

Big Bang Theory

• The Big Bang theory is the accepted scientific theory about the origin of the universe.
• This theory is based on multiple lines of evidence.
• The Big Bang theory is one of the most popular attempts to describe the early universe.
• The theory was first proposed by Belgian astrophysicist and priest Abbe Georges Lemaitre (1894-1966).
• The name "Big Bang" was coined by British astronomer Fred Hoyle in 1949.
• All matter and energy were compressed into a single point (singularity) at the time of the expansion.

Expanding Universe and Abundance of Elements

• Includes light elements, heavy elements, and heavier elements than iron.

Major Types of Nucleosynthesis

• Primordial nucleosynthesis, or Big Bang nucleosynthesis.
• Stellar nucleosynthesis.
• Supernova nucleosynthesis.

Primordial or Big Bang Nucleosynthesis

• During primordial nucleosynthesis protons, neutrons, and electrons were moving around without control.
• In the first three minutes of the rapid expansion of the universe, rapid cooling, thus slowing down sub-atomic particles.
• Slowing down sub-atomic particles created more opportunities for binding together to form light elements.

Isotopes of Hydrogen

• Isotopes are atoms of the same element with the same number of protons and electrons but a different number of neutrons.
• Deuterium (D) is an isotope of hydrogen, formed from the fusion of a proton and a neutron, emitting a high-energy photon (γ).
• Tritium (T), or hydrogen-3, is produced from the fusion of two deuterium nuclei and a release of a proton and is unstable.

Stellar Nucleosynthesis

• Stellar nucleosynthesis is the process by which elements are created within stars by combining protons and neutrons from light elements.
• Stars, mainly made of hydrogen and helium, act as sites for nuclear reactions that fuse light elements to form heavier elements.
• Stellar nucleosynthesis is responsible for the creation of heavy elements up to iron, including boron, carbon, and nitrogen.

Supernova Nucleosynthesis

• Supernova nucleosynthesis is the process by which heavier elements than iron (Fe) are created.
• Extreme temperature and abundant neutrons allow to make Heavier elements than iron
• Supernova stars can reach 100 Billion°C, which is 6000x hotter than the core of the sun.

Periodic Table

• Dmitri Mendeleev examined the relationship between atomic masses and the physical/chemical properties of elements.
• Mendeleev believed that atomic mass was the most fundamental property for classifying elements.
• Mendeleev arranged known elements by increasing atomic masses and their properties.
• In 1913, Henry Moseley discovered that atomic number is the most fundamental property, not atomic mass.
• Moseley's discovery changed the perspective of elements and their properties.
• Mendeleev's periodic law was modified into the modern periodic law based on atomic number.