Our environment is made up of chemical compounds. Yes, everything is a chemical! (mind blown)
Our environment is made up of chemicals
Example: Water is a chemical that is essential to life
Natural and human processes change the chemical composition of the environment
Name three natural processes and three human processes that alter the chemical composition of the environment
All living things are made up of chemicals
Therefore all living things depend on chemicals to survive
ex. plants and animals cannot carry out cellular respiration without oxygen
However certain chemicals can also harm the environment, either produced naturally or by human activity
ex. volcanoes release large quantities of carbon dioxide, sulfur dioxide and ash – all chemicals
ex. Gasoline used in cars and pesticides used for crops all add harmful chemicals to the environment
Elements (Ex. oxygen) are pure substances that cannot be broken down into other substances. Elements can join together and form chemical compounds (O2, H2O, CO2).
Living things use and reuse chemical compounds “trading” them back and forth like a trading card.
Repeatedly trading elements back and forth throughout an ecosystems forms a cycle.
Almost all organisms need nitrogen. It comprises about 78% of the air we breath, yet we can’t use it!
Free nitrogen aka nitrogen gas (N₂) is pretty boring, and non-reactive.
Free nitrogen has to be made usable or ‘fixed’
Nitrogen fixation the process of changing free nitrogen (N₂) so that the nitrogen atoms can combine with other elements to form compounds that organisms can use (NO₂, NH₄)
Plants cannot use free nitrogen (N₂); they can only use nitrogen when it is combined with other elements like hydrogen and oxygen.
Bacteria located on roots of some plants separate nitrogen atoms so that they are free to combine with other elements to be used by plants.
Plants use nitrogen-containing compounds
Animals eat these plants
Animals’ bodies use the nitrogen to make more complex substances like proteins
Decomposers break down the large nitrogen-containing molecules into simpler nitrogen compounds in dead organisms and waste.
Some nitrogen-containing compounds are broken down by bacteria in the soil and released into the air as free nitrogen.
The cycle begins again.
Invented the Haber process, whereby nitrogen can be fixed synthetically. This invention alone has increased the yield of food stocks, if you are alive and eating there’s a good chance it’s due to this man!
Additionally, Fritz also invented the use of chlorine gas as a chemical weapon, which was used in the first world war. Chlorine gas binds with the mucous of your lungs to create Hydrochloric Acid.
Conversion to free nitrogen by bacteria
Becoming dissolved in water which carries it away or deep into soil, unreachable by plants
Harvesting of plants (no decomposition of plants on farmer’s field)
Some examples of natural processes that change environmental chemicals
Your body's metabolism
Any change in the environment that produces a condition that is harmful to living things.
Releases chemicals into the air and soil
Some of these chemicals can be broken down naturally; some cannot and cause long-term problems, becoming major issues.
Any subject of importance about which people have strong, conflicting, points of view.
A substance that enriches soil so that plants will grow better. Bags of fertilizer show 3 numbers in this format
ex 10 -15 - 20 (first is N, second is P, third is K)
Contains 3 main elements: nitrogen, phosphorus, and potassium. Sometimes contains a fourth element: Sulfur.
Fertilizers can be natural or synthetic (man-made)
Too much fertilizer will damage organisms or ponds, streams and lakes that it enters through runoff.
General term for chemicals used to kill pests. Pests are organisms (Plant or animal) that harm people, crops or structures.
Herbicides kill or control weeds.
Insecticides kill or control insects.
Fungicides kill fungi.
Pesticides are non-selective, meaning they kill pests and non-pests
Can stay in the environment for a long time
Is the garbage collected from households, industrial plants and commercial buildings; from machinery to plastic bottles.
Most is place in landfill sites
Hazardous wastes are burned in incinerators (thus, contributes to air pollution)
Sanitary landfill sites have plastic liners and compacted clay that prevent rainwater and groundwater with dissolved wastes in them from leaking into the soil.
Some solid wasted are reused or recycled
Sewage - is wastewater containing dissolved and undissolved materials from your kitchen, bathroom and laundry.
Sewage moves by pipes to septic tanks or a sewage treatment plant.
Septic tank - is an underground container where bacteria break down the organic materials before it is moved out to the soil.
Sewage Treatment Plants - treat wastes from homes, businesses and industries.
Storm sewers - are large pipes that collect the large amounts of rainwater from street drains, which go directly into rivers and lakes without treatment.
Treated wastewater released into rivers and lakes.
Is the burning of fossil fuels (formed from dead plants and animals).
Fossil fuels that are mainly made up of the elements hydrogen and carbon
Coal (C₂₄₀H₉₀O₄NS) , Gasoline (C₈H₁₈) and natural gas (CH₄)
Release large amounts of carbon dioxide and water vapour, as well as sulfur dioxide, nitrogen oxides and traces of mercury and lead which are pollutants.
Natural gas processing (common in Alberta)
Natural gas is composed of compounds like methane, ethane, propane and butane, also nitrogen gas, carbon dioxide, hydrogen sulfide, helium and traces of mercury.
Natural gas is processed to separate these components
Natural gas containing hydrogen sulfide (sulfur - think smelly farts!)
Natural gas not containing hydrogen sulfide
Human bodies need 25 elements
Carbon, oxygen and hydrogen are the most common elements of living things, they form:
Sugar / Starch
Fat / Oils / Wax
Molecules that contain carbon (there are a few exceptions!!)
Molecules that do not contain carbon.
There are many more organic than inorganic compounds on Earth!
Any element or compound that organisms uses for living, growing and reproducing.
There are about 9 nutrients that organisms need in large amounts:
Carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, magnesium, calcium and sulfur.
Nutrients that organisms need in small or trace amounts, for example, selenium.
Too little, but also too much of a nutrient can be damaging
Optimum amounts of a substance is the amount that provides an organism with the best health.
Recall that there are 4 important classes of organic compounds:
Lipids (AKA fats)
General term for organic molecules made up of carbon, hydrogen and oxygen.
Simple carbohydrates aka ‘sugars’ a few examples:
Complex carbohydrates aka ‘carbs’ a few examples:
Starches (C₆H₁₀O₅)ᴺ - A Glucose chains
Cellulose (C₆H₁₀O₅)ᴺ - B Glucose chains
Glucose is a simple sugar made by plants through photosynthesis.
Starch, cellulose and glycogen are composed of many glucose molecules joined together.
General term for organic molecules made up of many carbon, hydrogen and oxygen atoms. (C₅₅H₁₀₄0₆)
fats, oils and waxes
our skin produces oils / plants produce corn and peanuts that contain a lot of oils.
General term for organic compounds made up of amino acids; protein molecules contain nitrogen, hydrogen, oxygen and carbon, sometimes sulfur.
Used for growth, repair and energy
They are the main component of enzymes.
Catalysts that control chemical reactions in organisms (Salivary Amylase, Protease)
The building blocks of proteins
Each protein contains its own number and arrangement of amino acids (between 40 and 500 amino acid units)
20 different kinds of amino acids are common in protein molecules
The largest and most complicated molecules found in living things.
All cells contain 2 important nucleic acids:
i. Deoxyribonucleic acid (DNA)
ii. Ribonucleic acid (RNA)
These 2 are made up of phosphates, a simple sugar called ribose and nitrogen-containing molecules.
These 2 play a major role in heredity and cell’s activities.
There are different tests to use when testing for different organic molecules.
Benedict’s solution - turns from blue to yellow-orange-red in the presence of organic molecules.
Iodine solution - turns from red-brown to blue-black.
Fats and oils - leave a spot on brown paper that light can pass through.
Biuret solution - turns from blue to purple to mauve.
Plants and animals rely on their environment
Plants take in inorganic compounds to make organic compounds
Consumers rely on plants and animals to obtain the compounds they need
Does not require a plant to use energy. Includes 2 processes: diffusion and osmosis.
The movement of molecules from an area of high concentration to an area of low concentration. ( evening out or balancing of the concentration of substances.)
When water moves from an area of high concentration to an area of low concentration.
When plants require energy to move nutrients from areas of low concentration to areas of high concentration.
The process of taking food into our bodies.
Organisms break down food mechanically as in chewing, and chemically as with the use of enzymes in the mouth, stomach and small intestines.
The reaction of a substance with water. ‘Hydro’ refers to water and ‘lysis’ refers to breakdown.
A substance has been hydrolyzed when it has been broken down by hydrolysis.
Nutrients are absorbed through cell membranes and into the blood stream.
A compound that dissolves in water to form a solution with a pH lower than 7.
Think vinegar or lemon juice.
A compound that dissolves in water to form a solution with a pH higher than 7.
Think milk or hair bleach
The pH number of a solution indicates its acidity; it is a measure of the concentration of hydrogen ions (H-) in a solution.
pH range is usually from 0 to 14
pH of 1 is very acidic; for example battery acid
pH of 14 is very basic or alkaline; for example household ammonia
pH of 7 is neutral (neither an acid or a base); for example water
The difference between one number and the next on the pH scale represents a 10-fold difference (logarithmic scale)
meaning that a solution with a pH of 9 is 10 times more basic than a solution with a pH of 8.
also, a solution with a pH of 2 is 10 times more acidic than one with a pH of 3
1. A pH meter is a probe attached to a meter. You submerge the probe in the liquid and get a pH reading on the meter.
2. Acid-base indicators are substances that change colour when they are placed in solutions.
blue litmus paper turn red in an acid
red litmus paper turns blue in a base
3. A Universal indicator is a mixture of indicators that change colour over a wide pH range. You add a few drops of the indicator and compare its colour change with the colour chart to determine its pH.
Is the reaction between an acid and a base that produces water and salt (neutralization products).
Neutralizing the Effects of Acid Rain
Acid rain is formed By the following:
When sulfur dioxide combines with water to form sulphuric acid
When nitrogen oxides combine with water to form nitric acid
When carbon dioxide dissolves in water to form carbonic acid.
This water than falls as acid rain.
Ordinary rainwater is slightly acidic with a pH of about 5.6; acid rain can have a pH of 3.
Lakes can be neutralized by adding lime (calcium hydroxide). The acidic water and the basic lime react forming water and salt (neutralization products)
Acid / Base Lab
Anemones attach themselves to rocks and capture food with tentacles.
The material on which an organism moves or survives.
Some organisms are attached tot their substrate, like the sea anemone.
Other organisms obtain nutrients from their substrate.
Bread mould breaks down the molecules of its substrate, the bread, to obtain nutrients.
A layer of ozone (O3) in the atmosphere 15 to 50 km above the Earth’s surface protecting it from the Sun’s ultraviolet radiation.
Monitoring - means keeping track of something for a specific purpose.
- Chemicals are monitored to protect our water and air quality.
Write down words you don't know
Write down science vocab you have already encountered
Cloudiness in lakes is caused by increase in algal growth, which reduces the oxygen content of the lake affecting organisms that live there.
Clarity is not a good indicator of water quality because some chemicals and organisms cannot be seen with the naked eye.
Water quality is determined according to the use of the water.
Human drinking water
Recreation such as swimming
Livestock drinking water
Protection of aquatic life
Indicator organisms include fish, plants, worms, insects, plankton (microscopic algae and tiny animals), protozoa, bacteria and viruses.
Microscopic organisms like bacteria can cause serious health problems when present in large enough numbers.
Are animals without backbones that live in water
A large number of these harmful bacteria can cause illness
Includes insects, crustaceans (shrimp), worms and molluscs (clams).
These organisms are used because they indicate different conditions of the water, for example, oxygen levels, temperature and pH.
Diversity of organisms decreases as pH increases and dissolved oxygen decreases.
The number of different species in an ecosystem.
These are most commonly monitored as indicators of water quality:
Plant and nutrients (N, P)
Salts (NaCl, MgS)
Chemicals are measured in parts per million (ppm) or milligrams per litre (mg/L)
One part per million means that one unit of an element or chemical can be found in one million units of solution.
To solve how many ppms there is in a solution, use these steps.
Begin with 'X' part per 1000 parts solution (sometimes the question begins this way)
Find the percentage of part 1 (X/1000)
Now multiply part 2 by one million
If you had 25 pieces defective in a shipment of 1,000 pieces.
Then 25/1000= .025 or 2.5% of that shipment is defective.
Now calculate that percentage by one million. 0.025 X 1,000,000 = 25,000 PPM.
Suppose you make a food colouring solution by putting 99 mL of water in a beaker and adding 1 mL of food colouring.
The concentration of food colouring in this beaker is 1 part food colouring per 100 parts solution, which is 1% or 0.01.
Now calculate that percentage by one million. 0.01 X 1,000,000 = 10,000 PPM.
1. Suppose I have 100g of a salt solution, and the solution has 205 ppm of NaCl (Salt). How many grams of salt is there in the solution?
2. First write out 205 ppm in a g/1,000,000 format = 205g/1,000,000g.
3. Now multiply the ratio from step two by the amount of solution in step one. 100g x 0.000205 = 0.0205g
4. In the 100g of salt solution there is 0.0205g of NaCl present.
parts per billion (ppb) and parts per trillion (ppt) exist but the use of special equipment is necessary and only extremely hazardous substances are measured to this level, for example PCB’s.
Turbulence due to wind, speed
Amount of photosynthesis by plants and algae
Number of organisms using the oxygen
5 mg/L (= 5ppm) of dissolved oxygen supports most organisms
Invertebrates found in water are determined by the amount of dissolved oxygen.
High concentrations of phosphorus and nitrogen affect the amount of dissolve oxygen.
Sewage and runoff from fertilizers increase the growth of algae and green plants. As they increase, more die. This organic matter is now food for bacteria, using up more oxygen. Oxygen decreases, fish and aquatic insects cannot survive.
From earlier, rain and snow have a normal pH of 5.6 because of CO2 in the air dissolving in them
As acidity increases, organisms decrease, for example, most fish disappear when the water’s pH fall to 4.5
When acidic deposits build up in ice and snow during winter. Once it melts in spring, the acid meltwater flows into aquatic systems lowering its pH level.
Some pesticides have long-term effects, but most are designed to last only one growing season, to be broken down by bacteria therefore are no longer toxic.
Many cause pesticide-resistant pests to develop and quickly, because of their rapid reproduction
Can remain in tissues of organisms
Allow biomagnification to occur
Can become mixed together to form a more toxic.
Toxins: (poisons) are substances that produce serious health problems or death when introduced into an organism.
Toxicity: describes how poisonous a substance is.
A measurement used to compare toxins. LD means lethal dose, ‘50’ represents 50%. LD50 is the amount of a substance that causes 50% of a group of test animals to die if they are given a specified dose of the substance all at once.
The more toxic a substance is, the lower the LD50 number is.
Different types of chemicals affect organisms in different ways
This compares the toxicity of different substances because it is comparing the dosage that will produce death.
Metals that have a density of 5g/cm3 or more, meaning they are5 times or more heavier than an equal volume of water.
Include mercury, copper, zinc, lead, cadmium and nickel.
These metals occur naturally and are made into everyday items like tires. batteries and fertilizers
Affect the normal development in children, as well as causing permanent brain damage or death.
Air quality is determined by:
measuring the levels of pollutants in the air
estimating the amount of emissions from pollution sources (forest fires, industrial plants)
Forms when oxygen combines with sulfur
Causes smog and acid rain
Affects the respiratory system (throat and lungs) and irritates the eyes
Sources include burning fossil fuels (coal, oil, natural gas)
Are used to reduce SO2 emissions by 99%. SO2 reacts with limestone that converts it to gypsum used in manufacturing.
Formed when nitrogen monoxide gas (NO) reacts with oxygen to form NO2, a brown gas
Causes smog and acid rain
Affects the respiratory system and eyes
Sources include combustion in vehicles, generating plants, industrial processes
Forms when there is not enough oxygen to produce CO2, it has no colour and no odour, thus called the ‘silent killer’
Affects the amount of oxygen content carried by blood cells, causing headaches, sleepiness, chest pains, brain damage and death
Sources include combustion in vehicles, wood, natural gas, industrial processes and cigarette smoking
Reacts with oxygen, nitrogen oxides and volatile organic compound (VOCs) (organic chemicals that evaporate easily) with the presence of heat and sunlight, it is a colourless, odourless gas
Affects people who have lung diseases (asthma, even a cold!), breathing problems and long-term lung damage especially for developing children
Affects crops (wheat, soybeans, onion) and can causes rapid deterioration in plastic
Sources include fuel combustion in vehicles and industry
Effects the entire globe
Causes ozone depletion and climate change from the increase in CO2
- Not a pollutant because of its natural presence but increases in concentration making it dangerous
Atmospheric gases in the air trap heat from the Sun’s radiant energy
These (greenhouse) gases are water vapour, CO2, methane, and NOX
Is the greenhouse effect but greater, with more gases trapping more heat, increasing the Earth’s temperature (global warming)
Water vapour and CO2 are the 2 main contributors to the enhanced greenhouse effect
Can lead to climate change, violent storms, flooding and the spread of disease
Caused by human activities and natural events (volcanic eruptions, forest fires), increasing the concentration of greenhouse gases
Absorbs ultraviolet radiation (UV) protecting the Earth’s surface
Forms naturally 15 to 50 km above Earth’s surface
As the layer thins, holes can be created allowing more UV radiation through
Causes human skin cancer, cataracts
Are chemicals that react with UV radiation creating other chemicals that react with ozone and then destroying it
One chlorine atom will react with 100 000 ozone molecules
The hole over the South Pole was created because the ice particles in the atmosphere speeds up the reaction that destroys ozone molecules
CFCs are found in refrigerators, aerosol cans, fire extinguishers