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Science Presentation: Environmental Chemistry
Transcript of Science Presentation: Environmental Chemistry
is made up
that can Support
Group 4: Annalisa, Noah, Kirk, Justin, Hazel
1.1 Chemicals in the Environment
1.2 Acids and Bases
If you have an upset stomach you might want to take an antacid to help neutralize the acid, this reaction that occurs is called neutralization.
Neutralization - is a reaction between an acid and a base that produces water and a solid compound salt.
Salt - is a compound produced in a neutralization reaction between an acid and a base.
Acidic lakes are sometimes treated with lime (calcium hydroxide) to help neutralize them. If a lake gets too acidic (a pH number lower than 4.6) the fish in the lake will begin to die.
For example, if a strong base spills from a tanker truck a weak acid can be used to help neutralize it.
1.3 Common Substances Essential to Living Things
Our bodies need around 25 elements for normal growth. Carbon (C), Oxygen (O), and Hydrogen (H) are the most common chemicals in living organisms. These elements can make up complex molecules that form sugar, starch, fat, oil, wax, and proteins.
All living things needs nutrients to survive and live out in the wild. Plants contain nutrients such as carbon, hydrogen, and oxygen. They also obtain nitrogen, phosphorus, potassium, magnesium, calcium, and sulfur from the soil. These nine elements are called macronutrients since they are needed in large amounts. Elements such as selenium are also essential to plants and animals but they are only needed in small amounts, so they are called micronutrients.
1.4 How organisms Take in Substances
Plants take in inorganic compounds to make organic compounds. Consumers rely on organic compounds made by plants for their energy, growth, and repair. When organisms take in these compounds, other substances are taken. These substances may be
Nutrients enter the roots by diffusion - the movement of molecules from an area of high concentration to an area of low concentration. This action continues until the areas are equal concentrations. (No energy is required for this to occur).
Water moves through plants by a special type of diffusion, called osmosis. In this process, water moves through the walls of the plant's roots from an area where there are more water molecules to an area where there are fewer water molecules. As the plant uses the water, it draws more up from its roots.
Where organisms live affects how and when they can obtain nutrients. Some organisms get the nutrients they need by restricting other organisms from getting the same nutrients which reduces the competition.
A substrate is the material on which an organism moves or lives. Some organisms attach themselves to the substrate while others obtain their nutrients from their substrate.
Plants need high concentrations of nutrients such as nitrogen, sulfur, potassium, and phosphorus in their roots. These nutrients have higher concentrations in the roots than in the surrounding soil. To maintain these high concentrations, plants move more nutrients into their roots from areas of lower concentration (in the soil) by a process called active transport. This process requires energy.
25 different elements are used by humans for growth and function. The process of taking food into our bodies is called ingestion. Most of the ingested food is broken down chemically in the digestive system by a process called hydrolysis. A substance that has been broken down by hydrolysis has been hydrolyzed.
Maltose + Water ------> Glucose
C12H22O11 + H2O ------> 2C6H12O6
Nutrients such as glucose and amino acids are absorbed through cell membranes and into the bloodstream, which carries them to where they will be used or stored.
For example, the bread mould breaks down the molecules of its substrate, the bread, to obtain nutrients from it.
Nitrogen Fixation - is the process of changing free nitrogen (that has a triple bond) so that the nitrogen atoms can combine with other elements to form compounds that organisms can use. Nitrogen can only be fixed by lightning or legumes.
Fertilizer - is a substance that enriches the soil. so that plants will grow better.
On a bag of fertilizer a labeling shows what major elements that bag contains. For example:
# # # #
nitrogen phosphorus potassium sulfur
Pesticides - are chemicals used to kill pests.
Pest - is an organism that harms people, crops, or structures. Pesticides are grouped to the pest they kill. Herbicides kill or control weeds. Insecticides kill or control insects. Fungicides kill fungi.
Without pesticides in use, it is estimated that around 50% of the worlds food production would be lost to pests. But pesticides do not only kill pests, they can kill non-pest as well. For example- the bertha armyworm is a pest to canola. But spaying for armyworms can also kill bees that pollinate the canola.
The Nitrogen Cycle - is the process of how nitrogen circulates through the environment. It starts off as free nitrogen in the air. The waste that animals and plant produce, decomposes into the soil. Afterwards, the decomposers break down the waste and release nitrogen compounds into the the soil. The nitrogen can move from organisms and back to the soil several times. Eventually some nitrogen-containing compounds are broken down further by other bacteria in the soil. This nitrogen is released back into the air as free nitrogen, and the cycle begins again.
1.1 Continued-Agricultural Activities
- is the amount of a substance that provides an organism with the best health.
-are compounds whose molecules contain carbon, such as fossil fuels.
-are compounds whose molecules do not contain carbon.
Four importanat classes of organic compounds are: carbohydrates, lipids,proteins, and nucleic acids.
- Are organic molecules made up iof carbon, hydrogen, and oxygen. Some examples of carbohydrates are pasta, potatoes, rice, fruits, and bread. They can form simple molecules, such as sugar, or large and complex molecules such as, startch, cellulose, and glycogen.
- Are organic molecules made up of atoms of carbon,hydrogen,and oxygen. Lipids are also insoluble in water. Some examples of lipids are waxes,oils,and fats.
-Are organic compounds made up of units called amino acids, which are the building blocks of proteins. Protein molecules conatin atoms of nitrogen,hydrogen,carbon,and oxygen. Proteins are also the main component of enzymes.
Nucleic Acids-Are the largest and most complicated molecules found in all the cells of living things.The two most imporant ones are DNA (deoxyribonuleic acid) and RNA (ribonucleic acid). They are made up of phosphates,ribose,and nitrogen conatining bases. Nucleic Acids play a major role in hereditary and in controlling a cells activitys.
1.1 Continued-Solid Wastes
Soild waste can be anything from machinery to bottle caps. Solid wastes can be reused or recycled but most of it ends up in a landfil. Some hazardous wastes are burned in special plants called incinerators, those incinerations burn at very high temperatures, it is believed that incinerators contibute to air pollution.
Sanitary Landfills- are especially built to prevent waste chemicals from leaching into the soil. Two kinds of liners can be used to prevent the leaching, compacted clay or plastic liners.
All living things are made of chemicals and depend on chemicals to survive. Without carbon dioxide and water, green plants could not produce sugar for food. Without oxygen, plants and animals could not carry out cellular respiration.
Not all living chemicals that form the environment support living things. Forest fires and volcanoes release large quantities of carbon dioxide, sulfur dioxide and ash, which can be harmful to living things. Many chemicals that we use can cause harm.
Acid - is a compound that dissolves in water to form a solution with a PH lower than 7
pH - is the number of a solution indicating its acidity.
Base - is a compound that dissolves in water to form a solution with a pH higher than 7.
So to sum up the terms above, when a number is lower it is more of an acid, when it is higher it is more of a base.
Substances that are neither acidic nor basic, such as water, are said to be neutral.
Acid-Base Indicators - substances that can change colour when they are placed in solutions. For example, blue litmus paper turns red in an acid, and red litmus paper turns blue in a base.
- Wastewater is drain water containing both dissolved and undissolved material from your kitchen, bathroom, and laundry. This wastewater is called sewage.
travels through pipes in urban area and is dumped into sewage treatment plants or in a large septic tank. A
is a Container usually underground that uses bacteria to break down organic material before it is put into soil. A
sewage treatment plant
treats sewage and/or street drain water from rural areas which is drained into lakes or rivers. The treated wastewater is also known as
and may contain nitrogen and phosphorus from the breakdown of the sewage. If the sewage treatment plant cant handle a large quantity of rain water, the water will go into storm sewers which are large pipes that may lead dirrectly to a lake or a river. Water from storm sewers contain chemical such as oils, vehicle fluids, and salt.
Fuel Combustion/Industrial processes
Fuel combustion: Fossil Fuels- is fuel formed from dead pants and animals; coal, oil, and natural gas.When fossil fuels are burned the general reaction equation for combustion is:
hydrocarbon + oxygen------>carbon dioxide+water+energy
The combustion of fuels may cause polluntants to be released such as sulfer dioxide, nitrogen oxides, and traces of murcury and lead into the air.
The combustion of methane and propane:
Methane+oxygen------>carbon dioxide+water vapour+energy
Propane+oxygen----->carbon dioxide+water vapour+energy
Consumers are most familiar with fuels made from crude oil and natural gas. Before the use of these modern fuels consumers burned coal as enerygy.
Industrial processes: Processes such as production of fertalizer, power generation, and mineral processing may cause harmful pollutants to be released into the air. Natural gas production is a common industrial process. Natural gas is broken into its seperate compounds. Propane, butane, and methane are all seperated parts of natural gas and are mostly used for heating and burning. Ethane is used for making plastic such as
Natural gas is also processed to eliminate hydrogen sulphide an extremely poisonous chemical. Natural gas containing hydrogen sulfide is called
. Natural gas containing no hydrogen sulfide is called