Unit 1 Global Climate Change Pt. 1 Flashcards
chemistry
Chemistry: the scientific study of matter
matter
Matter: every object in the universe is composed of matter. Defined as anything that occupies space and has mass (substance). All matter consists of elements/atoms.
atoms
Atoms: all matter consists of atoms. The smallest units that retain all of the properties of their type of matter. In nature, atoms are not often found in isolation. Instead, they are usually bonded to each other to form molecules.
molecule
Molecule: a group of two or more atoms held together by covalent bonds.
elements
Elements: all matter is composed of individual elements. Substances that cannot be broken down into other substances by chemical reactions. Individual elements combine in a fixed ratio to form compounds.
There are 92 naturally occurring elements on earth and several others have been artificially created in the laboratory
The periodic table of the elements is a list of all known elements.
compounds, reactants and products
Reactants: starting matter
Products: ending matter
Compounds: substances with two or more elements in a fixed ratio.
cellular respiration
Cellular respiration: series of chemical reactions that uses oxygen gas and a sugar called glucose to provide energy to your living cells, releasing water and carbon dioxide as by-products.
the periodic table of elements
The periodic table of the elements: lists all of the chemical elements, ordered by atomic number.
4/92 naturally occurring elements make up the vast majority of matter within living organisms/living cells.
Another 7 elements account for much of the remaining mass.
14 trace elements are present in very tiny amounts, but cells cannot survive without them.
Only 25/92 are used by living cells.
trace elements
Trace elements: also called micronutrients, are any chemical element required by living organisms in miniscule amounts, but cells require them to survive.
atomic number
Atomic number: the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
atomic weight
Atomic weight: the number of protons plus neutrons in an atom, represented as an average of naturally occurring forms of the element.
solvent and solution
Solvent: a dissolving agent in a solution.
Solution: a liquid consisting of a homogeneous mixture of two or more substances.
water and its importance
Due to its polar structure, water is an extremely effective solvent, able to dissolve just about anything.
Liquid water readily absorbs and releases heat and water therefore, resists temperature changes more than most substances. The presence of water can thereby act to moderate temperatures.
On a global scale, the oceans help moderate the Earth’s surface.
On a personal scale, sweating helps moderate your temperature by cooling off your skin.
cohesion and adhesion
Cohesion: The attraction between molecules of the same kind.
EX: due to hydrogen bonding, water molecules tend to stick to each other.
Through cohesion, the effect of all these hydrogen bonds is to create surface tension, a film-like surface on which items (such as this spider) can be suspended.
Adhesion: the clinging of one substance to another, causes water to stick to surfaces, such as rain droplets on a car windshield. By means of hydrogen bonding.
Most of the chemical reactions that maintain life occur in water.
aqueous solution
Aqueous solution: is one that contains a substance dissolved in water. A solution in which water is the solvent.
A small percentage of the water molecules break apart into hydrogen ions (H+) and hydroxide ions (OH-).
Substances dissolved in water may also add H+ ions to the solution.
The concentration of H+ ions in an aqueous solution determines its pH.
the pH scale
The pH scale: The concentration of hydrogen ions in a solution. ph measure of the relative acidity of a solution. Runs from 0 (most acidic) to 14 (most basic) with 7 as neutral. Each number in the pH scale represents a tenfold change in H+ ion concentration.
acid
Acid: is a chemical that when dissolved in water, releases H+ ions.
EX: your stomach contains hydrochloric acid, HCI.
In solution, it tends to break apart into H+ and C1-.
Acids have a pH between 0-7
burning fossil fuels and CO2 levels
releases chemicals that react with the water in the air to form strong acids and as they fall back to earth in the form of snow, rain or fog, the acid precipitation damages lakes and soil.
As CO2 levels rise in the atmosphere, about 25% of the excess is absorbed by the oceans and as it dissolves CO2 undergoes a chemical reaction that lowers the pH of the ocean and as this happens, ecosystems are destroyed because this limits the ability of organisms to perform the chemical reactions used to build their skeletons or shells.
base
Base: is a chemical that when dissolved in water, removes H+ ions from solution, usually by combining them with OH- to form water molecules.
Lye is sodium hydroxide, NaOH and in water, the molecule falls apart and the released OH- combines with H+ decreasing the concentration of H+ ions in the solution. Bases have a pH between 7 and 14.
buffers
Buffers: most cells regulate their pH through this. A chemical substance that resists changes in pH by accepting hydrogen ions from or donating hydrogen ions to solutions.
Consists of weak acids and weak bases.
Within human blood and other fluids, there are several different types of buffers that keep the body’s solutions at a nearly neutral pH, despite changes in the concentration of H+.
EX: contact solution protects eyes from potentially painful changes in pH.
ecology
Ecology: is the scientific study of how organisms interact with each other and with their environment
The study of ecology is important because all of us are affected by our ecosystems in countless ways.
Biologists sometimes refer to the study of life on this scale as “skin-out” biology, meaning that ecology is concerned with the levels of biological organization from an organism outward into its environment.
environmentalism
Environmentalism: a broad philosophy and social movement that seeks to maintain environmental quality.
The science of ecology can inform an understanding of our environment– a necessary first step toward solving environmental problems.
Five levels of ecology
Five levels of ecology
Organismal ecology
Focuses on ways organisms adapt to their environments through physiology and behavior
Population ecology
Focuses on environmental factors that affect population size, growth and density.
Community ecology
Focuses on interactions between species and how this affects the makeup and organization of the community.
Ecosystem ecology
Focuses on questions of energy flow and chemical cycling
Biosphere
population, community, ecosystem and biosphere
Population: a group of individuals of the same species living the same geographic place at the same time.
Community: consists of all the populations (of multiple species) living in a particular place.
Ecosystem: is all life living in a particular area together with all the nonliving components of that environment, including water, minerals and physical factors such as light and air.
Biosphere: is the global ecosystem–all life and all of life’s environment. The biosphere is the sum of all ecosystems on Earth which includes the lower atmosphere, the land and all water.
