ENVS 101 1st Edition Lecture 5 Outline of Last Lecture I. Introduction to Time and Change: Catastrophism and the principle of UniformitarianismII. How old is the Earth? History of the Earth, how it has changed, and age estimateIII. Life from a planetary perspective: Evolution, the History of LifeIV. Cambrian “Explosion” Stromatolites and the first living organismsOutline of Current Lecture V. Introduction to Materials of the EarthVI. Organic Matter of the EarthVII. Composition and internal Structure of the EarthVIII.Introduction to MineralsCurrent LectureMaterials of the EarthOf the various materials which are found throughout the Earth, there are three states of matter that we are most familiarized with: Solids, Liquids, and Gases. Despite these simple categorizations, the materials of each category are vastly different, and incredible variety is even found between materials of the same state. For example: Water and Lava are both liquid, however, various factors set them apart from each other. While lava has a complex molecular structure with partial bonds (making it an extraordinarily viscous liquid), water has a very uniform molecular structure by contrast. Liquids have a defined form, but an undefined shape. Liquids will conform to whatever container they are put into.Gases, another material found on Earth, are essentially free molecules, that cannot be contained, and have an undefined shape and form. By comparison, solids have both a defined shape and a defined form.Chemical Elements: Are the most fundamental substances into which matter can be separated.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Atom: Is the smallest individual particle that remains in the distinctive properties of a given chemical element. They are built of protons and neutrons (in the nucleus), with electrons orbiting around the nucleus.Atomic Number: The number of protons in the nucleus of an atom.The sum of neutrons and the protons is what makes the atomic mass. Therefore, the electrons found within an atom are considered massless particles. Isotopes: Are atoms with the same atomic number, but with different mass numbers from the original form of the atom. Some isotopes are radioactive, and can be used in radioactive dating.An atom is considered electrically neutral because positive charges in the protons balances out the negative charge found in the electrons.Ion: An atom that has excess positive or negative charge.Cation: A positive ion Anion: A negative ionCompounds are formed when both anions and cations combine and form a bond.Molecule: The smallest unit that retains the properties of a compound.Carbon Isotopes found throughout the Earth include the following varieties: 12C, 13C, and 14C. Thevast majority of the carbon in Earth is of the 12C variety.Organic Matter found throughout the Earth is what makes up living organisms. The word “organic” applies to compounds consisting of carbon atoms that are bonded together by covalent bonds. “Organic” also implies that the compound is biotic in origin. A common characteristic of organic compounds is that:- They tend to occur in long chain-like structures that are called polymers.Important bio-polymers in the Earth system include the following: - Proteins: Chains of bonded amino acids- Nucleic Acids: For example, DNA, which is comprised of nucleotides- Carbohydrates: The basis for most food that we eat, a carbon-hydrogen-oxygen based compound.- Lipids: Another family of organic molecules that are not polymers, including fats, oils, phospholipids, steroids, and waxes.Composition and Internal structure of the Earth: The layers of the Earth are distinguished by their composition, rock strength, and state of matter. There are Compositional Layers, as well as Mechanical Layers that categorize the various layers of the Earth. The Compositional/Mechanical layers are listed as follows, from the innermost to the outermost layers: Compositional Layers:- Core (6396 kilometers)- Mantle (2900 kilometers)- Oceanic Crust (5-7 kilometers)- Continental Crust (10-70 kilometers)Mechanical Layers:- Inner Core - Outer Core- Mesosphere (660 kilometers)- Aesthenosphere- Lithosphere (10-200 kilometers)The three major compositional layers of the Earth are:The Core: A metallic iron solid inner and liquid outer core.The Mantle: Consisting of dense, rocky matter.The Crust: Thin, less dense rocky matter.The core and the mantle have nearly constant thicknesses, but the crust varies in place to place.The continental crust and oceanic crust of the Earth also differ in their composition. - The continental crust is felsic: granitic, enriched in Si (silicon) and K (potassium), lighter in color, and less dense. - By contrast, the oceanic crust is mafic: balsatic, enriched in Fe (iron) and Mg (magnesium), and is darker and color and more dense compared to the continental crust.The Mesosphere: Is known as the “middle sphere” or “lower mantle.”The Aesthenosphere: Is known as the “weak sphere” in the uppermost mantle.The Lithosphere: Is known as the rocky space found in the uppermost mantle.Introduction to MineralsMinerals are the building blocks of the geosphere, they are or have:- Naturally formed- Inorganic- Solid- Have a specific chemical composition- Characteristic crystal structure (because of the way in which atoms are