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60 Cards in this Set

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Three Subatomic Particles

(Names, Locations, Charges, Mass)
Protons are located in the nucleus and have a positive charge
Neutrons are located in the nucleus also and have no charge
Electrons orbit the nucleus and have a negative charge and are much lighter than neutrons and protons
What is an atom?
the smallest unit of matter
What is matter?
anything that has mass and takes up space
Every atom has a _____ charge. Why?
Neutral. Because since there is an equal number of neutrons and protons, the positive and negative charges balance out, which in turn creates a neutrally charged atom.
What is a chemical element?
A pure substance that consists entirely of one type of atom; cannot be broken down into other substances by chemical means
What are elements represented by
Elements are represented by one or two letter symbols and are organized into the Periodic Table
What are isotopes identified by?
Their mass number
What is atomic mass?
the average mass of an element's isotopes
Because they have ___________, all...
Because isotopes have the same number of electrons, they all have the same chemical properties
What are radioactive isotopes?
Their nuclei are unstable and break down at a constant rate over time; they release energy as their nucleus breaks down
Uses for radioactive isotopes
Determine the ages of fossils and rocks
Detect and treat cancer
Kill bacteria that causes food to spoil
What is atomic number?
the number of protons and electrons in an atom
What are isotopes?
Atoms of the same element that differ in the number of neutrons that they contain
What is an ion?
an ion is a charged atom because of the unbalanced amount of electrons compared to protons. This becomes unbalanced because an atom loses electrons (becomes positively charged) or gains electrons (becomes negatively charged)
What is a compound?
A substance formed by the chemical combination of two or more elements in a fixed ratio
What is a molecule?
the smallest unit of most compounds; atoms joined with covalent bonds
What is a covalent bond?
The moving electrons travel about the nuclei of both atoms; the electrons are shared
What is an ionic bond?
One or more electrons are transferred from one atom to another; the electrons are transferred; one atom is positively charged and the other becomes negatively charged
What are valence electrons?
Valence electrons are the electrons that are available to form bonds; enable carbon to form chains that are almost unlimited in length
What is adhesion?
It is an attraction between molecules of a different substance

Ex: water molecules' and glass molecules' cohesion
Water's polarity
Water is polar because there is an uneven distribution of protons (there are more in the oxygen nucleus than there are in the hydrogen nucleus)
What is a solution?
in a solution, the components are evenly distributed throughout it

Ex: Koolaid
What is a mixture?
a material composed of two or more elements or compounds that are physically mixed together but not chemically combined

Ex: trail mix
What is a solute?
the substance that is dissolved in the solution

Ex: sugar and powder/Koolaid mix
What is a solvent?
the substance in which the solute dissolves

Ex: USUALLY WATER
pH scale divisions
Bases are above 7
Neutral is 7
Acids are below 7
OH- and H+
Basic have more OH- ions

Acids have more H+ ions

Neutrals have an equal amount of OH- and H+ ions
What does the pH scale measure/indicate?
It measures the concentration of H+ ions in a solution; percent hydrogen
What is the purpose of buffers?
they are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
Saturated vs. Unsaturated
Saturated Fats have no double bonds

Unsaturated Fats have at least 1 carbon-carbon double bond
What is the reactant in a chemical reaction?
the elements or compounds that enter into a chemical reaction
What are the products in a chemical reaction?
the elements or compounds produced by a chemical reaction
What is activation energy?
The energy that is needed to get a reaction started
What is a catalyst?
A substance that speeds up the rate of a chemical reaction
What is so special about carbon compounds?
Carbon atoms have 4 valance electrons, which allow them to form strong covalent bonds with many other elements

One carbon atom can bond to another, which gives carbon the ability to form chains that are almost unlimited in length
Carbon atom structure
Can form single, double, or triple bonds with other carbon atoms
What are the 4 types of macromolecules?
Lipids
Proteins
Nucleic Acids
Carbohydrates
Explain the structure of an enzyme.
Enzyme-substrate complex: the substrates, the reactants of enzyme-catalyzed reactions, bind to a site on the enzyme called the active site. The substrates and active site have complementary shapes and the fit is so precise that it is often compared to a lock and key
What can affect the activity of an enzyme
Temperature
pH
Regulatory molecules
What is the function of enzymes?
Speed up chemical reactions that take place in cells
What are some naturally occurring elements?
Hydrogen
Iron
Carbon
Selenium
What are the four most abundant elements in the body?
Oxygen
Carbon
Hydrogen
Nitrogen
What does a chemical formula state?
The number of each element in a compound
Explain Van Der Waals Forces and give an example
It is an attraction between a positively charged molecule and a negatively charged molecule

Ex: In a gecko, each tiny hair on its feet is attracted to the oppositely charged molecule on glass; geckos can walk against gravity
What is a chemical reaction?
Transformation of one set of chemicals into another
What has to happen in a chemical reaction?
you have to start and end with the same number of atoms on each side
Hydrogen bonding and polarity result in what?
Cohesion (sticking to itself), adhesion (sticking to other things), capillary action (trees), surface tension (bug is able to walk on water), ice floats, specific heat (holds/releases head slowly; lake effect)
What is a suspension?
a mixture of water an a non-dissolved material

Ex: blood
What is the pH scale based upon?
10x changes
Which type of bond is the weakest?
Hydrogen bonds are the weakest
What is heat capacity?
the amount of heat energy required to increase its temperature
Which are more likely to start spontaneously and why?
Reactions that release energy because they do not need a source of energy to begin reacting
How do compounds differ from their individual elements?
The physical and chemical properties are very different
How do you find the atomic number, atomic mass, mass number, number of electrons/protons/neutrons?
Atomic # = number of protons/electrons

Mass # = number of protons and neutrons found in the nucleus of an atom; atomic mass rounded to the nearest whole number

Atomic mass = number on periodic table

Neutron number = subtract atomic number from atomic mass
What is water's overall charge?
Neutral
What is a hydrogen bond?
The attraction between a hydrogen atom with a partial positive charge and another with a partial negative charge
How does water's polarity contribute to its physical properties?
Water's polarity causes it to expand upon freezing and the ability to dissolve
How does water's polarity influence its properties as a solvent?
Water's polarity gives it the ability to dissolve both ionic compounds and other polar molecules
What does organic chemistry mean?
the study of compounds that contain bonds between carbon atoms
Describe polymerization.
Macromolecules are formed by this process. The larger compounds, polymers, are built by joining together smaller ones, monomers.