41 terms

Chapter 2 Environmental Systems: Matter, Energy, and Change

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Matter
anything that occupies space and has mass
Mass
- defined as a measure of the amount of matter contained in an object
Atom
- the smallest divisible unit of an element that can be made where that element still retains all its chemical and physical properties.
Elements
- a substance composed of atoms that cannot be broken down into smaller simpler units which differ in their chemical and physical properties.
Compound
- a substance that is composed of more than one type of element.
Mass Number
the number of protons in an element which is unique to each type of element
Isotope
Atoms or molecules of elements which differ by the number of neutrons in the nucleus
Radioactive Decay
The process where unstable isotopes disintegrate by releasing energy and subatomic particles to obtain a more stable state.
Half-life
the time it takes for one half of the molecules of a radioactive isotope to decay to a more stable state.
Covalent Bonds
a bond between two different atoms where a pair of electrons is shared and exist in the physical space of both atoms.
Ionic Bonds
a bond that is formed between two different atoms where one atom is negatively charged,
Hydrogen Bonds
An weak bond that is formed between hydrogens that have a partially positive charge due to the unequal sharing of electrons in a "polar" covalent bond with an electronegative element such as oxygen or nitrogen.
Surface Tension
- A property of water that is due to the cohesive force created by the hydrogen bonding seen between water molecules.
Capillary Action
The ability of water to move up a narrow orifice because of the adhesiveness of water attributed to its' ability to form hydrogen bonds with other polar substances.
Cohesion
The hydrogen bonding between like molecules as seen in water.
Adhesion
The hydrogen bonding between different substances and water.
pH
the measure of the number of free hydrogen ions in as solution of water.
Law of Conservation of Matter
In any chemical reaction, the amount of matter doesn't change; matter is neither created or destroyed.
Inorganic Compounds
Molecules that do not contain hydrogen and carbon.
Organic Compounds
Molecules that contain hydrogen and carbon.
Carbohydrates
Compounds that contain carbon, hydrogen and oxygen in the ratio (CHO)n. Large polymer known as polysaccharides are made up of subunits such as glucose and serve as structural or energy storage molecules in cells.
Proteins
- Large molecules in life which are a polymer of amino acid subunits. Enzymes are proteins which catalyze biochemical reactions involved in obtaining energy and building biomolecules.
Lipids
Molecules necessary for the structure of cell membranes and are insoluble in water.
Nucleic acids
Polymers of nucleotides that hold the code for synthesizing all components of the cell. DNA. RNA is a nucleic acid important for the synthesis of proteins.
Cell
The smallest unit of all life.
Electromagnetic Radiation
The form of energy that the sun emits and includes visible light, UV light, xrays, radio wave, microwaves. Different forms of light differ in their relative amount of energy and wavelength.
Energy
- the capacity to do work.
Power
the rate at which work is done...energy/time
Potential Energy
energy that is stored and available to do work.
Kinetic Energy
- the energy of motion or that found available when matter moves from one location to another.
1st Law of Thermodynamics
Energy cannot be created or destroyed
2nd Law of Thermodynamics
When energy changes from one form to another, a certain amount is unavailable to do work and is transformed into thermal energy. When transforming energy from one form to another the degree of disorder increases.
Energy Efficiency
The ratio of the work done to the total amount of energy introduced in the system.
Energy Quality
The ease with which energy is available to work.
Entropy
All systems move toward an increase in disorder unless additional energy is applied
Open/Closed System
Open system with regard to energy is one where energy can leave or enter the system. A closed system contains all the energy available and none will enter from outside the system. This can also be evaluated similarly with regard to mass.
Systems Analysis
- When the flow of all energy and mass is tracked with regard to inputs and outputs. Indicates how energy and matter flows through an environment.
Steady state
When the input of energy or matter equals the output in an open system.
Feedback loop
The adjustments a system makes to the input and output flows and energy and matter.
Positive Feedback Loop
the response of a system to a change enhances the change and results in a greater change from the original state. Example increase in population in a species
Negative Feedback Loop
- The response of a system to a change results in the system resisting change by returning to its original state. Ex. Effect of drought on evaporation from a lake.