today we will learn the basics of chemistry in life science
Atoms, Elements, and the periodic table
Metals, semimetals (metalloids), and nonmetals.
Further grouping: transition metals, rare earths, alkali metals, alkaline earth, halogens, and noble gasses.
An element is a pure substance that is made up entirely of one type of atom.
reading atomic symbols
The atom is the basic unit of matter.
Atoms are made up of protons, neutrons, and electrons.
Protons and Neutrons are particles that are bound together by strong atomic forces and for the center of the atom, we call it the nucleus.
Protons have a positive charge
Neutrons carry no charge
Protons and electrons have around the same mass.
Electrons are negatively charged, they are 1/1840 of the mass of a proton.
Electrons in constant motion around the nucleus of the atom.
Electron are arranged in a series of orbits called shells:
The shells can only hold a certain number of electrons.
The first shell can hold two electrons.
The second shell can hold up to eight electrons.
Atoms have an equal number of protons and electrons, so all atoms are electrically neutral because the positive charge f the protons and the negative charge of the electrons cancel out.
Are atoms of the same element that contain different number of neutrons. They have a different mass.
Sometimes atoms gain or lose electrons. The atom then loses or gains a "negative" charge. These atoms are then called ions.
Positive Ion - Occurs when an atom loses an electron (negative charge) it has more protons than electrons.
Negative Ion - Occurs when an atom gains an electron (negative charge) it will have more electrons than protons.
The following image shows Na losing an electron and Cl gaining an electron
Thus the Na becomes Na+
The Cl becomes Cl-
Form when atoms transfer electrons between each other, forming ions that are electrically attracted to each other forming a bond between them. Sodium chloride (NaCl) is a typical ionic compound.
A polar bond is a covalent bond between two atoms where the electrons forming the bond are unequally distributed. This causes the molecule to have a slight electrical dipole moment where one end is slightly positive and the other is slightly negative.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Atoms can share between two and six electrons.
Van der Waals FOrces
Dipole: a pair of equal and oppositely charged or magnetized poles separated by a distance.
What is an ecosystem?
An ecosystem involves all living and no-living components in an area. Energy flows and matter cycles through an environment.
Atmosphere: this includes the wind speed and direction, humidity, light intensity and quality, precipitation and temperature.
Biotic Factors: These are all the living organisms in the environment, including their interactions.
Abiotic factors: elements that are not alive: soil, rocks, mountains, rain, clouds
Living organisms interact with each other in their habitat, they influence matter by walking around and moving things around.
Habitat: the natural environment in which a creature lives including the biotic and abiotic factors.
Each organism occupies a niche, an ecological niche of an organism is their function in the ecosystem: where they live, what organisms they interact with, how they respond t changes in the health of the environment.
Tolerance rage: each species has a tolerance range, this is their comfort zone, at what point they move to another environment.
CONTAMINANTS CONTRIBUTE to acid rain
Acid rain: rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm, typically to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulfur and nitrogen oxides, which combine with atmospheric water to form acids. -Oxford
Normal, clean rain has a pH value of between 5.0 and 5.5, which is slightly acidic. However, when rain combines with sulfur dioxide or nitrogen oxides—produced from power plants and automobiles—the rain becomes much more acidic. Typical acid rain has a pH value of 4.0.
Acid Rain has been known to damage natural ecosystems
The Earth has Slope, gradient, and Topography
In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line.
Topography is the study of the shape and features of land surfaces.
Water Basin Vocabulary
Watersheds are involved in many cycles
What is PH and why does it matter?
The term pH refers to the acidity or alkalinity of a solution.
Substance that release hydrogen ions when dissolved in water are acids.
The more hydrogen ions they release the more acidic they are.
Substances that release hydroxide ions when dissolved in water are bases.
Alkalinity increases with the concentration of hydroxyl ions.
Each pH unit represents a 10-fold change in concentration.
We will compare the pH of the following:
Baking Soda Solution
Record your results in your worksheet
Why does pH matter?
In general, fish reproduction is affected at pH levels below 5.0
Fish begin to die when pH falls below 4.0
A pH change of 1 means a ten fold change in the ions.
pH 9 is ten times more basic than pH 8
pH stands for potential of hydrogen, a measurement of the acidity r alkalinity of a solution
7 is neutral
1 to 6 are acids
8 to 14 are bases
Acids are substance that break apart in water to form a hydrogen ion.
Acids react with carbonates to give off carbon dioxide
Bases are substance that break down in water and form hydroxide ions (OH-).
The greater the concentration of OH- ions the stronger the base is.
Have a pH from 8 to 14
pH 9 is ten times more basic than pH 8
More on Acids and Bases
Some plants tell us the pH of their soil by expressing different colors of flowers.
Venom is Acidic
A sting from a bee may be painful for many reasons, pH of bee venom is 5.0-5.5
Formic acid in ants has a pH of 2 to 3
Ph can be different in various parts on an environment
Find the connections between these concepts
A concept map helps us see the connections between words and concepts, you can present a concept map as a web, a tree, in circles, any way you would like. A concept map is a form of creative self expression.
The shoreline of most continents is naturally lined with a network of plants and animals.
We see coral reef and mangroves, coral reef systems are where about 75% of tropical fish begin their lives. Here we find starfish, sea sponges, turtles, a huge variety of sea creatures. Coral are a symbiotic relationship between an type of algae named zooxanthellae and a type of animal, calcite is secreted by the animal to make the coral reef structures that we see, the algae gives coral the color that we see and when there is coral bleaching it means that the symbiote algae has left the coral. Beautiful sites such as coral reefs are valuable for ecotourism and scuba diving. Many coral species glow thanks to green fluorescent protein (GFP), this protein is used as a biomarker in biomedical research.
As the ocean transitions into the land we see mangroves, these trees have large roots that essentially hold the coastline in place, they dig deep into the earth and absorb more carbon dioxide than most trees making them a carbon sink. Mangroves are threatened by deforestation and shrimp farming.
Natural habitats are homes to thousands of creatures and slow down erosion, especially during complex weather patterns that cause storms like El Niño. These trees live in salt water and create a brackish environment where organisms that like semi-salty water can live. Many animals that live in these environments have amazing regenerating abilities, many salamanders live in brackish water. A type of salamander that lives in brackish water but not on the coast is the Axolotl, they are only found in lake Texcoco in Mexico where a saltwater spring makes the water salty. Axolotls have helped us learn more about stem cells because they are able to regenerate any body part, this research has contributed to stem cell therapy for humans.
Shorelines and COasts of the Continents
Coral Reefs live along the edges of continents
So do Mangroves
What is coral?
Coral is a symbiotic relationship between a polyp which is a type of animal and an algae called zooxanthellae. The polyp secretes calcite and builds the coral reef.
Coral Reef Health
In warmer water the zooxanthellae leave the polyp and this causes coral bleaching. Bleached corals are at risk of dying because the algae photosynthesizes and gives the polyp sugars that help it survive.
Coral Restoration Efforts
corals glow using Green Fluorescent Protein
Starfish live in the same area and have been known to REGENERATE parts of their body
This diverse ocean ecosystem neighbors the Mangroves
Mangrove roots are large and prevent erosion
Mangrove ecosystems are destroyed for shrimp farming
Mangrove trees are a powerful carbon sink, they take in large amounts of co2 and hold it in their roots and branches, parts of living matter are called biomass
We call this biosequestration
Biosequestration is the process of capturing and storing carbon in living organisms such as plants and algae
Blue carbon is the term for carbon captured by the world's ocean and coastal ecosystems.
Natural Weather Patterns lead to Land Erosion
Mangroves produce oxygen, reduce carbon dioxide, and reduce erosion
Mangroves are able to live in salt water and secrete salt through their leaves
Saltwater dehydrates most roots through osmosis but mangroves are able to live in it
Specialized glands remove excess salt and create brackish water, semi-salty water, where many creatures can thrive such as frogs and salamanders
Saltwater can travel underground and go to lakes through springs
Axolotls live in Brackish water that is not on the coast
Axolotls are salamanders that are known for tissue regeneration
They Help us develop biomedical advances through stem cell research
Author: Jazmin Gannon
A place to grow