Science 9: Unit C final

What is the difference between aerobic and anaerobic biodegradation?

Aerobic: environments that require or contain oxygen Anaerobic: environments that don't require or contain oxygen

Biodegradation

Breakdown of materials by organisms such as earthworms, bacteria, and fungi; ''bio-'' refers to living things and ''degrade'' means to break up

How would you clean up an acidic chemical spill?

By combining it with a base to neutralize it

List the four types of organic molecules and the molecules/substances that make up each type of organic molecule.

Carbohydrates: made up of carbon, hydrogen, and oxygen. Used to give us energy. Lipids: fats, oils, and waxes and are compounds composed of carbon, hydrogen, and oxygen atoms. Our bodies store food in the form of fat. Our skin also produces oils Proteins (amino acids): proteins are used for growth and repair and for energy. A protein is made up of amino acids. Proteins are the main component of enzymes Nucleic Acids: the largest and most complicated molecules. All cells contain two important nucleic acids which are DNA and RNA. DNA and RNA are made up of phosphates, ribose, and nitrogen containing molecules. Nucleic acids play a role in heredity and in controlling a cell's activities.

What potentially harmful gas is given off when fossil fuels are burned?

Carbon dioxide

What type of elements make up carbohydrates? What type of molecules can these atoms form?

Carbon, hydrogen and oxygen atoms can form simple molecules like sugar or complex molecules like starch, cellulose, glycogen

Which metals would be considered a heavy metal?

Copper, lead, zinc, mercury, cadmium, nickel

What is the difference between diffusion and active transport?

Diffusion: process in which molecules move from an area of high concentration to an area of low concentration Active transport: process in which plant cells use energy to move nutrient molecules from areas of low concentration to an area of high concentration

What problems are caused by ground-level ozone?

Especially harmful to people with lung diseases (eg: asthma or colds). Can be more harmful to children because their lungs are still developing. People exercising outside can also have breathing problems and long term lung damage. Can affect crops such as wheat, soybeans, and onions Can cause materials like plastics to deteriorate faster

How is ground-level ozone formed?

From reactions between oxygen, nitrogen, oxides and volatile organic compounds (VOCs), in the presence of heat and sunlight

In the lab on page 200 - 201, list the different tests that were used to test for the different organic groups. List which organic groups they were testing for.

Glucose: benedict's solution turns from blue to yellow-orange-red Starch: Iodine solution turns from red-brown to blue-black Fat/Oil: Fats and oils leave a spot on brown paper that light can pass through Protein: Bluret solution turns from blue to purple or mauve

List two ways that are used to test water quality.

Identifying which aquatic invertebrates are in the water. Different invertebrates prefer different living conditions. Processing samples to test for microscopic organisms which are sometimes harmful eg: Escherichia coli

What information does MSDS sheets contain?

Its composition, Physical appearance, Chemical characteristics, Precautions that should be taken when handling, using, transporting and disposing of the product

What substance is added to lakes affected by acid rain to raise the pH?

Lime (calcium hydroxide)

List the six essential macronutrients.

Magnesium, sulfer, potassium, phosphorus, nitrogen, calcium

How should you NOT dispose of chemicals?

Never pour them down the drain or into soil Never throw them into the garbage

List the elements/compounds that make up the air we breathe, along with the percentages they are found in.

Nitrogen (78%), Oxygen (21%), argon (less than 1%), carbon dioxide (.03%), traces of hydrogen and neon

What major chemicals are found in fertilizers?

Nitrogen, phosphorous and potassium

How is ozone helpful to humans?

Ozone layer absorbs ultraviolent radiation (UV) from the sun. This protects organisms on Earth from damaging UV rays.

What factors affect the distance and direction an airborne chemical will travel?

Pollutants properties; Wind speed Direction of prevailing winds

What is an example of photolysis?

The formation of ozone: nitrogen oxide in the presence of light breaks down to form nitrogen monoxide and an oxygen atom. The oxygen atom then combines with an oxygen molecule to form ozone.

How is ozone harmful to humans?

To people with lung diseases such a s asthma and anyone with a cold Children are at a higher risk because their lungs are still developing People who exercise outside may suffer breathing problems and long-term lung damage

What are the products of neutralization?

Water and a compound called a salt

List the greenhouse gases.

Water vapour, carbon dioxide, methane, nitrogen oxides

What does WHMIS stand for?

Workplace - Hazardous - Materials - Information - System

Pollution

any change in the environment that produces a condition that is harmful to living things

Photolysis

breakdown of compounds by sunlight; ''photo'' means light and ''lysis'' means breakdown

pesticide

chemical used to kill plants

Phytoremediation

clean up of the environment using plants; ''phyto-'' means plant and ''remediation'' means cleanup; plants have been used to clean up metals, hydrocarbons, and other chemicals

List the effects of the oil spill of the Exxon Valdez

commercial fishers could no longer fish people who relied on wildlife for food had to buy expensive groceries from the stores recreational users chose not to come to the contaminated area

base

compound that dissolves in water to form a solution with a pH higher than 7

acid

compound that dissolves in water to form a solution with a pH lower than 7

Organic compound

compounds whose molecules contain carbon, except carbon monoxide, carbon dioxide, carbonates and cyanides

Spring acid shock

concentration of acid that can dramatically lower the pH of the water in a pond, slough, lake, or river for a short period of time; occurs in areas where acid precipitation is a problem and acidic deposits build up in ice and snow in the winter; in spring, when the ice and snow melt, the acid meltwater flows into aquatic systems

Biomagnification

increase in concentration of a chemical or element as it moves up the food chain

Global warming

increased average temperatures worldwide caused by the enhanced greenhouse effect

dilution

mixing of a substance with water or air; this reduces the substances concentration

Sour gas

natural gas containing hydrogen sulfide

What two chemicals are essential for plant growth, but are major water pollutants?

phosphorus and nitrogen

nitrogen fixation

process of changing free nitrogen so that the nitrogen atoms can combine with other elements to form compounds that organisms can use

Neutralization

reaction between an acid and a base that produces water and a solid compound called salt

Dispersion

scattering of a substance away from it's source

fertilizer

substance that enriches soil so that plants will grow better

What five factors increase biodegradation?

temperature, pH, moisture , oxygen supply, nutrient availability

What does LD50 mean?

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. LD = lethal dose

Effluent

wastewater released from a factory or sewage treatment plant

Greenhouse effect

when radiant energy from the sun reaches the Earth's surface, much of it is reflected back into space. But some of this energy is trapped near earth's surface by a layer of gases that act like a glass in a greenhouse