1. Science & Technology in the Environment
Chemistry

2. Chemistry
15.01 – Define terms and the state, properties, and classification of matter related to density and the environment.

3. General Terms
Chemical
Chemistry
Matter
Mass
Volume
Energy

4. Chemistry Terms Chemical Chemistry Matter
A substance produced by or used in a chemical process
Chemistry
The study of the composition of matter and the energy created by the interaction of matter
Matter
Anything that has mass and volume

5. Chemistry Terms Mass Volume Energy The quantity of matter in an object
A measure of an object’s resistance to moving or being moved
Often determined by weighing with a scale
Weight and mass can be different in differing places
“altitude”
Volume
Means that something occupies space
Energy
The ability to do work or cause change

6. Energy Potential Kinetic
Energy of matter because of its position or compositions
It is stored in the matter
Kinetic
The energy of an object in motion

7. States of Matter Solid Liquid Gaseous Definite shape and volume
Examples: wood, stone, glass, etc.
Liquid
Has a definite volume and takes the shape of its container
Examples: water, oil, etc.
Gaseous
Has neither a definite shape or volume
Can expand and contract and move around
Example: air.
It can be made to fit in various shapes, like a tire, and can be compressed.

8. Why States of Matter Change
Matter may change from one state to another
Usually related to temperature and pressure
When water is cooled, it turns to ice, a solid
When water is boiled, it turns to steam, a gas
The properties do not change

9. Properties of Matter Property Two Properties
A characteristic or feature that makes it possible to distinguish between kinds of matter
Two Properties
Physical
Can be observed or measured without altering the matter
Mass, Color, Shape, Length
Chemical
Describes the changes matter goes through when its identity is altered or changed to create substances in different forms
Describes the change it undergoes in altering its identity.
Burning wood. Wood becomes ash and carbon dioxide, as well as heat and light.

10. Classification of Matter
Pure substances
Matter that has uniform and consistent composition and properties from one sample to another.
Salt and Sugar
Mixtures
A combination of two or more different kinds of matter, and it is not definite in the proportions of its contents.
Types
Solution – Homogenous mixture. Can be solid, liquid, or gas
Suspension – when particles are dispersed in a fluid medium.
Water in a stream.

11. Chemistry
15.02 – Discuss chemical elements, compounds, reactions, formulas, and equations.

12. Compounds Elements form compounds
Pure substances are either elements or compounds
Elements do not decompose
An element is a pure substance that cannot be broken down into other substances.
Examples: gold, silver, and iron

13. Elements
A substance consisting entirely of atoms of the same atomic number
Everything on Earth is made of chemical elements
114 chemical elements have been identified
92 are natural elements found on Earth
The rest are made in a laboratory

14. Names and Symbols All have a name and symbol
Symbols are either one or two letters
Some officially unnamed have three letters
Letters used are often letters from the English spelling of the word
AL for Aluminum
N for Nitrogen
O for Oxygen
C for Carbon
Some are from Latin
Ag for Silver, old name was argentum
K for Potassium
Fe for Iron

15. Organizing the Elements
Grouped in the Periodic Table
An arrangement of chemical elements in the order of increasing atomic number. It is in rows and columns.

16. Types of Elements Metals Nonmetals An element with metallic luster
Can be shaped
Are electrical conductors
Iron, Aluminum, and Copper
Nonmetals
Poor conductor of heat and electricity
Oxygen, Nitrogen, Carbon, and Sulfur
Eleven elements classified as nonmetallic

17. Types of Elements (continued)
Metalloids
Between metals and nonmetals both in the periodic table and in properties
Arsenic
Six elements classified as metalloids
Noble Gases
Do not normally react with other elements
Neon and Helium
Six elements are classified as noble gases.

18. Atoms, Atomic Number, and Masses
Small part of an element that can take part in a reaction
Atomic Structure
The arrangement of the parts of atoms
Atomic Number
The number of protons in the nucleus
Atomic Mass
The total number of protons and neutrons in the nucleus.

19. Chemical Reactions and Compounds
What occurs when a substance becomes another substance with different characteristics
Types
Composition – 2 or more substances react to form a more complex product
Decomposition – when chemical compounds break down
Single Replacement – when one element replaces another in a compound
Double Replacement – When two compounds exchange elements

20. Compounds
Forms when two or more elements unite to form a substance with qualities different from the elements alone
Chemical Bonding
New compounds are formed when elements bond
Chemical bonding is two or more elements joining together to form a compound.
Molecules
Smallest amount of a substance that can exist independently and keep the properties of the substance
Water – two hydrogen atoms and one oxygen atom
Calcium Carbonate (limestone) C2CO3
Carbon dioxide CO2
Glucose C6H12O6

21. Formulas and Equations
The combination of chemical symbols and numbers that depict a compound
Shows the element symbols and formulas, the reactants, and the products of a chemical reaction.
Example:
Photosynthesis Equation
12H2O + 6CO2 + sunlight and chlorophyll = C6H12O6 + 6O2 + 6 H2O

22. Chemistry
15.03 – Demonstrate the ability to determine the pH and salts of material and relate it to environmental conditions.

23. pH
Strength of hydrogen ion concentration, measured as potential hydrogen or pH
14 point scale is used
Water is neutral = 7
Solutions below 7 (0 to 6.9) are acid
Solutions above 7.0 (7.1 to 14) are basic or alkaline
The greater the distance from 7, or neutral, the stronger the substance.
9 is more basic or alkaline than 7.1
5 is more acidic than 6.9

24. pH Plants need the correct pH to grow properly
Different plants require different pH
Range is for most plants
Important for animals, especially fish
Relates to decomposition
Microorganisms cannot survive well in an improper pH and decay will be stopped
Acids are used to preserve food, like pickles in vinegar (acetic acid)

25. pH Measurements are normally performed with:
pH or litmus paper
pH meter
Most acids contain hydrogen
Sulfuric acid is H2SO4
Acetic acid (vinegar) is CH3CO2H
Bases produce hydroxide ions
React with acids to produce salts
Baking soda (sodium bicarbonate) NaHCO3 and limestone (calcium carbonate) CaCO3 are examples.

26. Salts Formed when acids and bases are combined
NaCl = table salt
Concentrations can build up in water and soil
Often by soil and water reacting
Example
Irrigation water containing a base is used on an acidic soil; can be on fields or in a container
Can result in unproductive land
Can also result from using certain fertilizers

27. Chemistry
15.04 – Discuss chemical sources of environmental hazards.

28. Chemical Sources of Environmental Hazards
Heavy Metals
An element with a high atomic weight or mass
Lead, mercury, and cadmium
Are poisonous in small amounts
Organic Compounds
Detergents – contained phosphates that caused phosphate build-up and damaged ponds
Pesticides – materials used to control pests
Petroleum – fossil fuel used in making gasoline, diesel fuel, lubricants, and other products.
Chloroflurocarbons (CFCs) – used in aerosols and refrigerants (AC and Fridge); may have contributed to the damage of the ozone layer

29. Chemical Sources of Environmental Hazards
Nonmetal Oxides
Elements whose oxides form acids
Sulfur forming into sulfur oxide and then reacting with water to form sulfuric acid
S + O  SO2 or SO3 + H2O  H2SO4
May cause air pollution
Radioactivity
Caused by the instability of the atomic nucleus of certain atoms
Radium decaying into radon, which can enter buildings and cause injury to people

30. Health Affects of Pollution