Unit C Environmental Chemistry: Section 1.0 Flashcards
(87 cards)
Can natural things be harmful to living things?
Yes many things like carbon dioxide are harmful but natural
What are elements?
Pure substances that cannot be broken down into anything further
What is the nitrogen cycle?
The way nitrogen moves through the environment and how nitrogen changes what atoms it is chemically bonded to
Can plants use nitrogen when it is bonded as a nitrogen gas, otherwise known as N2 (g)? If not, what other elements does nitrogen need to be bonded to?
Nitrogen can not be absorbed as N2 (g) in most plants. But when bonded to other elements such as hydrogen and oxygen, nitrogen becomes available to the vegetation.
Extra information that you will learn in higher grades:
The nitrogen sources taken up by higher plants are nitrate or ammonium as inorganic nitrogen sources and amino acids under particular conditions of soil composition. Nitrogen assimilation requires the reduction of nitrate to ammonium, followed by ammonium assimilation into amino acids.
Nitrate = Nitrates are composed of 3 oxygen atoms with a chemical NO3- formula
Nitrite = have 2 oxygen atoms that make up a chemical NO2- formula.
Ammonium = NH4+
Reduction means a loss of electrons, which makes the ions less negative.
re + duct + ion
back + lead + ending signifying noun in this case
We are “leading” the ion to go “back” to what it would have been, the opposite of oxidization that brought it there in the first place.
In what gaseous compound is nitrogen naturally found in?
N₂(g)
What is nitrogen fixation?
The process of changing free nitrogen so that nitrogen atoms can combine with other elements to form compounds that organisms can use
What does most of the nitrogen fixation?
Certain types of bacteria in soil located in root nodules
In what kind of plants are root nodules found in?
Beans, clover, and alfalfa
What do root nodules do?
They separate the nitrogen gas so it is able to pair with other elements such as hydrogen and oxygen for plants
What are the steps in the nitrogen cycle?
- Nitrogen fixation occurs
- Animals then eat the plants
- Their bodies use the nitrogen to make more complex substances
- Decomposers break down large nitrogen containg molecules in dead organisms and aniimal waste into simpler nitrogen compounds in the soil.
- Eventually some are broken down further by ground bacteria
- Then nitrogen is released back into the air as free nitrogen
What does the concentration of usable nitrogen in the natural environment depend on?
The root nodules, and carrying undissolved nitrogen deep in the soil
If soil lacks nitrogen what do farmers plant?
Nitrogen fixing plants
What is pollution?
Any change in the environment that produces a condition that is harmful to living things
What are some ways humans change the chemical balances in our environment?
Growing crops, solid waste, treating waste water, manufacturing products, and driving vehicles
What is a fertilizer?
A substance that enriches soil so plants will grow
What do the 3 numbers on fertilizer mean?
Nitrogen
Phosphorus
Potassium
What does the 4th number on a fertilizer mean?
it has sulfur added to it
What are pesticides?
Chemicals used to control pests
What is a pest?
An organism that harms people, plants, or structures
What do herbicides kill?
Weeds
What do insecticides kill?
Insects
What do fungicides kill?
Fungi
What is not good about pesticides?
Some are not selective so they end up killing good organsims
What is solid waste?
Garbage that is collected from households, industrial plants, commercial buildings and etc.
