Download 6.1 ATOMS, ELEMENTS, and COMPOUNDS

6.1 ATOMS, ELEMENTS, and COMPOUNDS
I. ___________________is the study of matter.
A. _______________ is anything that takes up space and has mass.
-Everything in the universe has matter.
-Matter is composed of __________________.
B. _____________ is the amount of matter that an object has.
-Mass and weight are not the same thing.
C. __________ is the pull of gravity on an object
II.
Composition of Matter
A. ___________________—pure substances that cannot be broken down
into simpler kinds of matter
• Made of one type of atom
• More than 100 elements (92 naturally occurring)
• 90% of the mass of an organism is composed of 4 elements
(___________________, __________________, ____________________,
___________________)
• Each element has a unique chemical symbol
-consists of 1-2 letter
-first letter is always capitalized
-Ex: O, C, F, Al, Ag, Mg
B. ________________—the simplest particle of an element that still has all the
properties of that element
 Atoms are so small that their true structure cannot be observed. Our
understanding of
 the structure of atoms is based on scientific models.
C. Parts of an atom
• The nucleus of an atom contains two types of
particles:
1. ___________________—positively charge
2. ___________________—has no charge, “neutral”
• The nucleus contains most of the mass of the atoms
• All atoms of a given element have the same number of protons
• The third particle of the atom is the electrons which is located outside the
nucleus in energy levels (electron clouds).
• ___________ have a negative charge.
• Number of protons is balanced by an equal number of electrons therefore there
is no charge of the atom.
• All atoms have this same basic structure.
Structure of an Atom
D. Neutrons
• The number of neutrons varies slightly among atoms for the same element.
• Atoms of the same element that have different numbers of neutrons are
referred to as _________________of that element
• Changing the number of neutrons does not change the overall charge of the
atom but can affect the stability of the nucleus causing it to decay or break
apart. Such isotopes give off radiation and referred to as “radioactive isotopes.”
E. Atomic Mass and Atomic Number
• Protons and neutrons each have a mass of ____________ (atomic mass unit) or
_________
• The _______________________ of an element is equal to the number of
protons plus the number of neutrons in the nucleus of the atom.
• The ____________________ of an element is equal to the number of protons.
F. Periodic Table
• The elements are arranged by their atomic number on the _________________.
• The horizontal rows are called _______________ and tell the number of energy
levels.
• The vertical groups are called ________________and tell the outermost number
of electrons.
G. Compounds
I. _________________________ are pure substances formed when two or more
different elements combine.
-Ex: H2O CO2, and C6H12O6
• Compounds are always formed from a specific combination of elements in a
fixed ratio.
• Compounds cannot be broken down into simpler compounds or elements by
physical means.
-can be broken down by chemical means into simpler compounds or into
their original elements
-H2O can be broken down into hydrogen gas and oxygen gas
• Elements can undergo chemical reactions to combine with other elements in
order to become __________________________.
• Stable elements have their outer energy level filled
III.
CHEMICAL BONDS
A. The force that holds atoms together is known as a chemical bond.
• __________________ are directly involved in the formation of chemical bonds.
-They travel around the nucleus of an atom in areas called ________________.
-Each energy levels has a specific number of electrons that it can hold at any
time
-The first energy level, closest to the nucleus, can hold up to ______ electrons.
-The second energy level can hold _______electrons.
-The third energy level can hold ________electrons.
B. Types of Chemical Bonds
1. ___________________—forms when atoms share one or more pairs of
electrons
• A ______________ is a compound in which the atoms are held together
by covalent bonds.
• Can be a single, double, or triple bond depending on number of pairs of
electrons shared.
2_____________________—forms when atom gives up electrons and another
receives electrons in order to become stable
• Electrical attraction between two oppositely charged atoms or groups
of atoms called _________________
• Most ionic compounds are crystalline at room temperature and have
higher melting points than molecular compounds formed by covalent
bonds.
• Ex. ____________________________
-both atoms are unstable
-to become stable, sodium gives away 1 electron and becomes positive,
chlorine receives 1 electron and becomes negative
• Some atoms tend to donate or accept electrons more easily than other
atoms.
• The elements identified as ___________________tend to donate
electrons.
• The elements identified as ___________________ tend to accept
electrons.
6.2 Chemical Reactions
Chemical reactions allow living things to grow, develop, reproduce, and adapt.
I.
Reactants and Products
A. Chemical Reactions
• A _________________________ is the process by which atoms or groups of atoms in
substances are reorganized into different substances.
• Clues that a chemical reaction has taken place include the
___________________________________________________________________
• Chemical bonds are ________________ and _______________ during chemical
reactions
B. Chemical Equations
• __________________________________ describe the substances in the reaction and
arrows indicate the process of change.
• _____________________ are the starting substances, on the left side of the arrow.
• ______________________ are the substances formed during the reaction, on the right
side of the arrow.
• Reactants
Products
• Glucose and oxygen react to form carbon dioxide and water.
• Is this equation written correctly?
• 6.2 Chemical Reactions
C. Balancing Equations
• The law of conservation of mass states matter cannot be created or destroyed.
• The number of atoms of each element on the reactant side must equal the number of
atoms of the same element on the product side.
• Balancing Equations—Practice
1. Fe + Cl2  FeCl3
2. H2 + O2  H2O
3. C2H6 + O2  CO2 + H2O
4. CO2 + H2  CH4 + H2O
II.
ENERGY
A. ___________________ is defined as the ability to do work or cause a change.
B. States of Matter:
• _______________—particles are packed tightly and move slowly
• _______________—particles move freely and take the shape of the container
• _______________—particles move rapidly and have no definite shape
C. Energy of Reactions
• The ___________________ is the minimum amount of energy needed for
reactants to form products in a chemical reaction.
D. Energy Changes in Chemical Reactions
• This reaction is exothermic and released heat energy.
• The energy of the product is lower than the energy of the reactants.
• This reaction is endothermic and absorbed heat energy.
• The energy of the products is higher than the energy of the reactants.
III.
ENZYMES
A. An enzyme is a ______________________________.
• A ____________________ is a substance that lowers the activation energy
needed to start a chemical reaction.
• It does not increase how much product is made and is not used up in the
reaction.
• The reactants that bind to the enzyme are called ___________________________.
• The specific location where a substrate binds on an enzyme is called the
_______________________________.
• The active site changes shape and forms the enzyme-substrate complex, which helps
chemical bonds in the reactants to be broken and new bonds to form.
B. Enzyme Action
1.
2.
3.
4.
• Enzyme Action
• Factors such as ___________________________________________ affect enzyme
activity.
• When enzymes are exposed to one of these factors, they may become
___________________________________.
• -Denaturing causes the enzyme to not be as effective or possibly quit
working altogether.
6.3 Water and Solutions
• The properties of water make it well suited to help maintain homeostasis in an
organism.
I. Water’s Polarity
A. Molecules that have an unequal distribution of charges are called
_______________________.
• Polar molecules have one side that has a positive charge and the other has a
negative charge.
• Water is a polar molecule.
B. Water molecules are held together by weak _____________________.
• A hydrogen bond is a weak interaction involving a
hydrogen atom and a fluorine, oxygen, or nitrogen atom.
• Hydrogen bonds are important in biological processes.
II.
Properties of water
A. __________________________ is the attractive force between particles of the same
kind. This property allows water to bulge from the top of a filled glass without spilling
over.
B. _________________________________ is the attractive force between unlike
substances.
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III.
A.
B.
C.
D.
E.
F.
G.
H.
IV.
Together these properties make it possible for water to move upwards against
the force of gravity in a narrow tube.
This phenomenon is called capillarity.
Mixtures with Water
_________________ -- a combination of ______ or more substances in which each
substance retains its individual characteristics.
________________________ --one that has a uniform composition throughout; a
solution.
__________________ -- a substance in which another substance is dissolved. (Ex: tea)
__________________ -- the substance that is dissolved in the solvent. (Ex: Sugar)
In a heterogeneous mixture, the components remain distinct.
a. In a __________________, the components will eventually settle to the bottom.
b. In a __________________, the particles will not settle over time. Examples
include fog, smoke, butter, mayonnaise, milk, paint, and ink.
________________ -- the measure of how much of a substance is dissolved.
__________________________ -- one in which nothing else can dissolve.
__________________________ -- water is the solvent.
Acids and Bases
A. Substances that release hydrogen ions (H+) when dissolved in water are called _______.
B. Substances that release hydroxide ions (OH-) when dissolved in water are called
_______.
C. The pH Scale
 The measure of ______________________________________________ pH.
o Ranges from ____________ with _____ being neutral.
 ____________________ have a pH values lower than 7.
o Have a sour taste
 ____________________ have pH values higher than 7.
o Have a bitter taste
 ____________________ are mixtures that can react with acids or bases to keep
the pH within a particular range.
o Help neutralize a body’s pH level
6.4 Organic Chemistry
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The element ______________ is a component of almost all biological molecules.
Carbon has _____________ in its outermost energy level.
One carbon atom can form ________________ covalent bonds with other
atoms.
 Carbon compound can be in the shape of
____________________________________________.
Draw Examples of Each
Macromolecules
o Carbon atoms can be joined to form carbon molecules.
o _________________ are large molecules formed by joining smaller organic
molecules together.
o _________________ are molecules made from repeating units of identical or
nearly identical compounds linked together by a series of covalent bonds.
Carbohydrates
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Compounds composed of carbon, hydrogen, and oxygen in a ration of one oxygen
and two hydrogen atoms for each carbon atom.
Values of n ranging from three to seven are called simple sugars, or
monosaccharides.
Two __________________ joined together form ___________________.
Longer carbohydrate molecules are called polysaccharides.
Lipids
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_______________ made mostly of carbon and hydrogen.
A ___________________ is a fat if it is solid at room temperature and an oil if it
is liquid at room temperature.
Lipids that have ______________________ with only single bonds between the
carbon atoms are called ___________________.
Lipids that have at least one ________________________ between carbon
atoms in the tail chain are called unsaturated fats.
Fats with more than one double bond in the tail are called polyunsaturated fats.
Proteins
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A compound made of small carbon compounds called amino acids.
___________________ are small compounds that are made of ____________________
______________________________________________________________________ .
Amino acids have a central carbon atom.
One of the four carbon bonds is with hydrogen.
The other three bonds are with an amino group (_________), a carboxyl group
(_________), and a variable group (______).
The number and the order in which the amino acids are joined define the protein’s
primary structure.
After an amino acid chain is formed, it folds into a unique three-dimensional shape,
which is the protein’s secondary structure, such as a helix or a pleat.
_____________________ are complex macromolecules that store and transmit genetic
information.
Nucleic acids are made of smaller repeating subunits called nucleotides, composed of
carbon, nitrogen, oxygen, phosphorous, and hydrogen atoms.