Physical Science Reviewer: Nucleosynthesis and Nuclear Fusion

Light Elements Production

• The process responsible for producing light elements in the universe is known as Big Bang nucleosynthesis.
• This occurred within the first few minutes after the Big Bang, resulting in the formation of hydrogen, helium, and trace amounts of lithium and beryllium.

Distant Galaxies and Spectra

• Edwin Hubble observed that nebulae were distant galaxies.
• He studied their spectra, leading to significant contributions to the understanding of the expanding universe and the classification of galaxies.

Isotope Definition

• A form of an element with the same atomic number but different atomic mass is referred to as an isotope.
• Isotopes can have varying numbers of neutrons, affecting their stability and radioactive properties.

Big Bang Hypothesis

• The concept of the universe originating from a gigantic explosion known as the Big Bang was hypothesized by Georges Lemaitre.
• This theory suggests that the universe has been expanding since its inception around 13.8 billion years ago.

Aristotle's Elements

• Aristotle proposed five basic elements: earth, water, air, fire, and aether (the heavenly fifth element).
• These elements were considered fundamental to explaining the nature of matter in ancient philosophy.

Basic Substances in Chemistry

• Basic substances that cannot be further decomposed in any chemical union are known as elements.
• Elements serve as the building blocks of all matter and cannot be broken down into simpler substances by chemical means.