Environmental Science (chapter 2)

Science

a field of study focused on discovering how nature works and using that knowledge to describe what is likely to happen in nature

Scientific Method

when scientists discover a problem, propose a hypothesis to explain the data, gather data to test the hypothesis, and modify the hypothesis if needed

Scientific Hypothesis

a testable explantation of data collected

Data

information to answer a question

Model

approximate physical or mathematical representation that is used to understand or explain behavior of complex natural systems

Scientific Theory

a well tested and widely accepted scientific hypothesis

Scientific Law

a well testes and widely accepted description of observations of what we kind always happening in the same way in nature

How does the use of scientific method benefit the validity of research

by using the scientific method structure, scientists bias is minimized and error is minimized. it also simplifies the process of discovery

Describe the relationship between engineering and science

science is the study of the world and it helps humans know and understand how the natural world works, whereas engineering is the application of laws and theories to produce tools and machines

What is the purpose of peer review

to check and double check other scientists’ work. it makes sure their research was not a fluke but real scientific law

Compare and contrast scientific theory and scientific law

both theories and laws are well tested and widely accepted. theories explain why something happens, whereas laws describe what happens

What are two limitations of scientific inquiry

it is used by humans and biases and it restricts what once can observe from the physical world

Matter

anything that has mass and takes up space

Element

a fundamental type of matter with an unique set of properties and that cannot be broken down into simpler substances by chemical mass

Compound

combination of two or more different elements held together in fixed proportions

Atom

the smallest unit of matter into which an element can be divided and still have its distinctive chemical properties

Isotope

elements that have the same atomic number but different mass numbers

Molecule

a combination of two or more atoms of the same or different elements held together by chemical bonds

pH

a measure of acidity

Organic compound

contain at least two carbon atoms combined with atoms of one or more other elements

Physical Change

no change in its chemical compound

Chemical Change

a change in the chemical composition of a substance

Chemical Reaction

a change in the chemical composition of a substance

Law of Conservation of Matter

whenever matter undergoes a physical or chemical change no atoms are created or destroyed

Describe what determines the pH of a substance and what the numbers assigned to pH signify

pH is determined by the amount of Hydrogen ions and hydroxide ions. a neutral solution has an acidity of 7. an acidic solution has a pH below 7 and a basic solution has a pH above 7

What are polymers and which organic polymers and which 4 organic polymers are essential to life

polymers are complex organic compounds linked together by chemical bonds; carbohydrates, proteins, nucleic acids, nucleotides

Compare and contrast chemical and physical changes

a physical change does not change the composition of matter, while a chemical change does

Explain how the law of conservation of mass applies to chemical and physical changes

the conservation of mass means that atoms cannot be created or destroyed. this is seen in a physical change when atoms are rearranged into spatial patterns and in chemical changes when atoms are arranged in different chemical combinations

Energy

the capacity to do work or to transfer heat

Kinetic Energy

energy associated with motion

Thermal Energy

kinetic energy associated with hear

Electromagnetic Radiation

when energy travels from one place to another in the form of waves formed from changes in electrical and magnetic fields

Potential Energy

energy stored up

First Law of Thermodynamics

whenever energy is converted from one form to another, no energy is created or destroyed

Second Law of Thermodynamics

whenever energy is converted from one form to another, it ends up with less usable energy

Which types of energy fall under the category of kinetic energy and why

thermal energy because it is the total kinetic energy of all atoms in an object. electromagnetic radiation because energy is traveling from one place to another

Why is electromagnetic radiation so important to many of the planets vital processes

it is both an energy source and regulator

Two examples of potential energy

rock in your hand, water in a dam

Describe how turning potential chemical energy from food to usable energy for mechanical, kinetic, and thermal energy relates to the two laws of thermodynamics

whenever energy is converted from one form to another, you end up with a lower quality energy because it takes the form of heat and flows into the environment. therefore, we cannot recycle high quality energy

System

any set of components that function and interact in some regular way

Feedback Loop

when an output is fed back into a system as an input

Ecological Tipping Point

when a natural system becomes locked into a positive feedback loop

Key components of a system

input, output, and function

How does a positive feedback loop work

a positive feedback loop happens because things go further and further away from equilibrium (blood clot)

How does a negative feedback loop work

negative feedback loops bring stuff back to equilibrium. for instance, when there is a lot of predators after a couple cycles there will be more prey