Transcript What particles are atoms made of?

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.
Scientists now know that atoms are actually made from even
smaller particles. There are three types:
proton
neutron
electron
How are these particles arranged inside the atom?
What is the structure of an atom?
Protons, neutrons and electrons are not evenly distributed in an
atom.
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.
The electrons are spread out
around the edge of the atom.
They orbit the nucleus in
layers called shells. Electrons
have a negative charge.
Labelling the atom
Properties of the particles of the atom
Bonding Fill-in the Blank
Word Bank
covalent
bonding
atoms
molecules
ionic
element
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 Blank
Word Bank
bonding
covalent
ionic
atoms
elements
molecules
compound
hydrocarbon
Use the work bank to complete the following sentences
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.
Macromolecules
Group
Carbohydrates
Lipids
Nucleic Acids
Proteins
Elements
Function
C, H,O
Main source of
energy
Store energy;
biological
membranes
Transmit genetic
information
C, H
C,H,O,N,P
C,H,O
Control chemical
reactions,
transportation of
substances into
and out of cells.
Monomer
(Subunit)
Monosaccharide
Example
Nucleotides (5carbon sugar,
phosphate group
and nitrogenous
base)
Amino acids
RNA & DNA
Glucose, fructose,
and starches
Glycerol and fatty Fats, oil, waxes
acids
C = Carbon; H = Hydrogen; O = Oxygen; N = Nitrogen; P = Phosphorus
Hemoglobin
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:
 have a pH below 7 and turns
universal indicator paper yellow,
orange or red
 form solutions containing
hydrogen ions (H+).
Hydrochloric acid is a strong
acid.
Acetic acid (vinegar) is a
weak acid.
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?