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60 Cards in this Set
- Front
- Back
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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 |
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What is an atom?
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the smallest unit o matter
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What is matter?
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anything that has mass and takes up space
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Every atom has a _____ charge. Why?
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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.
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What is a chemical element?
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A pure substance that consists entirely of one type of atom; cannot be broken down into other substances by chemical means
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What are elements represented by
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Elements are represented by one or two letter symbols and are organized into the Periodic Table
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What are isotopes identified by?
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Their mass number
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What is atomic mass?
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the average mass of an element's isotopes
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Because they have ___________, all...
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Because isotopes have the same number of electrons, they all have the same chemical properties
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What are radioactive isotopes?
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Their nuclei are unstable and break down at a constant rate over time; they release energy as their nucleus breaks down
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Uses for radioactive isotopes
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Determine the ages of fossils and rocks
Detect and treat cancer Kill bacteria that causes food to spoil |
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What is atomic number?
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the number of protons and electrons in an atom
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What are isotopes?
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Atoms of the same element that differ in the number of neutrons that they contain
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What is an ion?
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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)
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What is a compound?
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A substance formed by the chemical combination of two or more elements in a fixed ratio
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What is a molecule?
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the smallest unit of most compounds; atoms joined with covalent bonds
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What is a covalent bond?
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The moving electrons travel about the nuclei of both atoms; the electrons are shared
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What is an ionic bond?
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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
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What are valence electrons?
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Valence electrons are the electrons that are available to form bonds; enable carbon to form chains that are almost unlimited in length
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What is adhesion?
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It is an attraction between molecules of a different substance
Ex: water molecules' and glass molecules' cohesion |
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Water's polarity
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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)
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What is a solution?
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in a solution, the components are evenly distributed throughout it
Ex: Koolaid |
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What is a mixture?
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a material composed of two or more elements or compounds that are physically mixed together but not chemically combined
Ex: trail mix |
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What is a solute?
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the substance that is dissolved in the solution
Ex: sugar and powder/Koolaid mix |
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What is a solvent?
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the substance in which the solute dissolves
Ex: USUALLY WATER |
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pH scale divisions
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Bases are above 7
Neutral is 7 Acids are below 7 |
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OH- and H+
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Basic have more OH- ions
Acids have more H+ ions Neutrals have an equal amount of OH- and H+ ions |
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What does the pH scale measure/indicate?
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It measures the concentration of H+ ions in a solution; percent hydrogen
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What is the purpose of buffers?
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they are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
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Saturated vs. Unsaturated
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Saturated Fats have no double bonds
Unsaturated Fats have at least 1 carbon-carbon double bond |
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What is the reactant in a chemical reaction?
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the elements or compounds that enter into a chemical reaction
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What are the products in a chemical reaction?
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the elements or compounds produced by a chemical reaction
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What is activation energy?
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The energy that is needed to get a reaction started
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What is a catalyst?
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A substance that speeds up the rate of a chemical reaction
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What is so special about carbon compounds?
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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 |
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Carbon atom structure
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Can form single, double, or triple bonds with other carbon atoms
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What are the 4 types of macromolecules?
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Lipids
Proteins Nucleic Acids Carbohydrates |
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Explain the structure of an enzyme.
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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
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What can affect the activity of an enzyme
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Temperature
pH Regulatory molecules |
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What is the function of enzymes?
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Speed up chemical reactions that take place in cells
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What are some naturally occurring elements?
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Hydrogen
Iron Carbon Selenium |
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What are the four most abundant elements in the body?
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Oxygen
Carbon Hydrogen Nitrogen |
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What does a chemical formula state?
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The number of each element in a compound
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Explain Van Der Waals Forces and give an example
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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 |
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What is a chemical reaction?
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Transformation of one set of chemicals into another
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What has to happen in a chemical reaction?
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you have to start and end with the same number of atoms on each side
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Hydrogen bonding and polarity result in what?
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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)
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What is a suspension?
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a mixture of water an a non-dissolved material
Ex: blood |
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What is the pH scale based upon?
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10x changes
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Which type of bond is the weakest?
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Hydrogen bonds are the weakest
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What is heat capacity?
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the amount of heat energy required to increase its temperature
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Which are more likely to start spontaneously and why?
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Reactions that release energy because they do not need a source of energy to begin reacting
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How do compounds differ from their individual elements?
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The physical and chemical properties are very different
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How do you find the atomic number, atomic mass, mass number, number of electrons/protons/neutrons?
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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 |
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What is water's overall charge?
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Neutral
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What is a hydrogen bond?
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The attraction between a hydrogen atom with a partial positive charge and another with a partial negative charge
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How does water's polarity contribute to its physical properties?
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Water's polarity causes it to expand upon freezing and the ability to dissolve
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How does water's polarity influence its properties as a solvent?
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Water's polarity gives it the ability to dissolve both ionic compounds and other polar molecules
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What does organic chemistry mean?
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the study of compounds that contain bonds between carbon atoms
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Describe polymerization.
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Macromolecules are formed by this process. The larger compounds, polymers, are built by joining together smaller ones, monomers.
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