Matter & the Environment

Key Question

• Why is chemistry crucial or central to environmental science?– Chemistry is crucial to understanding how

pollutants cause acid rain.

– Chemistry solves many environmental problems.

– Chemistry is central to understanding water pollution, and wastewater treatment, etc.

BUILDING BLOCKS OF CHEMISTRY

Atoms and elements are the building blocks of chemistry

What particles are atoms made of?For some time, people thought that atoms were the smallest particles and could not be broken into anything smaller.

proton neutron electron

Scientists now know that atoms are actually made from even smaller particles. There are three types:

How are these particles arranged inside the atom?

Protons, neutrons and electrons are not evenly distributed in an atom.

The electrons are spread out around the edge of the atom. They orbit the nucleus in layers called shells. Electrons have a negative charge.

The protons and neutrons exist in a dense core at the center of the atom. This is called the nucleus. The nucleus has a positive charge.

What is the structure of an atom?

Labelling the atom

Properties of the particles of the atom

Bonding Fill-in the BlankWord Bank

bonding covalent ionic atoms element

molecules compound hydrocarbon

Use the work bank to complete the following sentences.

1. _____ are the basic units of matter.

2. _____occurs when atoms combine.

3. A chemical substance that cannot be broken down into substance with other properties is an _____.

4. Molecules are formed when atoms form a _____ bond, in which they share electrons.

Bonding Fill-in the BlankWord Bankbonding covalent ionic atoms elements molecules compound hydrocarbon

5. A combination of two or more atoms of the same or different types forms a _____.

6. When an electron is transferred from one atom to another an _____ bond is formed. 7. A _____ is a substance that is composed of atoms of two or more elements.

8. _____ are compounds that contain only hydrogen and carbon.

Use the work bank to complete the following sentences

MacromoleculesGroup Elements Function Monomer

(Subunit)Example

Carbohydrates C, H,O Main source of energy

Monosaccharide Glucose, fructose, and starches

Lipids C, H Store energy; biological

membranes

Glycerol and fatty acids

Fats, oil, waxes 

Nucleic Acids C,H,O,N,P Transmit genetic information

Nucleotides (5-carbon sugar,

phosphate group and nitrogenous

base)

RNA & DNA

Proteins C,H,O Control chemical reactions,

transportation of substances into and out of cells.

Amino acids Hemoglobin

C = Carbon; H = Hydrogen; O = Oxygen; N = Nitrogen; P = Phosphorus

The Water Molecule

• Water has a partial negative charge at one end, and partial positive charge on the other.

• Molecules with charges that are not distributed evenly are “polar”

The Water Molecule

• Hydrogen bonding– Is the attraction between a

hydrogen atom with a partial positive charge and another atom with a partial negative charge.

• Hydrogen bonds are not as strong as covalent or ionic bonds.

• Water is able to form multiple hydrogen bonds.

The Water Molecule

• Cohesion is an attraction between molecules of the same substance– It causes water

molecules to be drawn together, which is why drops of water form beads on a smooth surface.

The Water Molecule

• Adhesion is an attraction between molecules of the different substances.– Is responsible for

causing water in glass columns to rise.

The Water Molecule

• Heat capacity is the amount of heat energy that is required to increase the temperature of a substance.– Multiple bonds in water

molecules requires a large amount of heat energy to cause those molecules to move faster.

Solutions

• Are mixtures in which the components are evenly distributed throughout– The components of

mixtures are a:• Solute which is the

substance that is dissolved.

• Solvent which is the substance that dissolves the solute.

Solutions

• Water dissolves salts, sugars, minerals, gases and other solvents like alcohol.

• Water is the greatest solvent on Earth.

Acids, bases, and pH

Acids are substances that:

Hydrochloric acid is a strong acid.

Acetic acid (vinegar) is a weak acid.

have a pH below 7 and turns universal indicator paper yellow, orange or red

form solutions containing hydrogen ions (H+).

Acids, bases, pH

• Bases are compounds that produce Hydroxyl (OH-) ions in solution.

• Examples are oven cleaners and bleach

Acids, bases, and pH

• The pH scale– Is a measurement system that is used to indicate

the concentration of hydrogen (H+) ions in solution.

• The pH scale ranges from 0-14.– Solutions with a pH below 7 are acidic.– Solutions with a pH above 7 are basic.

• Each step on the pH scale represents a factor of 10.

What is the order of pH?