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54 Cards in this Set
- Front
- Back
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All of life's processes involve _____, the combining, exchanging, and breaking apart of the atoms and molecules of substances
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chemical reactions
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All matter is made up of _____
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atoms
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Something that is made up of just one kind of atom is called an _____
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element
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six most important elements to biologists are ...
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hydrogen,
oxygen, phosphorus, nitrogen, carbon, sulfur |
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atoms of the same element with a different number of _____ are called _____
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neutrons/mass number, isotopes
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Because they have the same number of _____, isotopes have the _____
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electrons, same chemical properties
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all atoms want to be _____, that's why they form _____
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stable, bonds
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electrons move about the nucleus in _____ or _____
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energy levels, electron clouds
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The first energy level can hold _____ electrons, the second _____, and the third _____
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2, 8, 18
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when the outer level is _____, the atom is _____ and cannot _____ with other atoms
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filled, stable, react
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this is an atom with either a positive or a negative charge
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ion
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ionic bond can break up in _____
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water
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_____ forms when electron is tranferred
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ionic bonds
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when electrons are _____, covalent bond forms
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shared
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a _____ is the sharing or _____ of electrons between atoms
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chemical reaction, tranfer
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a _____ is used to describe how acidic or basic a solution is
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pH scale
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higher proportion of hydrogen ions (H+) is _____ and has a pH _____ 7 on the pH scale
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acidic, below
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higher concentration of hydroxide ions (OH-) is _____ and has a pH _____ than 7
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basic, higher
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the carbon atom has _____ elctrons
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4 valence
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the _____ atom is essential to life's chemicals b/c it can form _____ with itself and other elements making possible many different _____
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carbon, covalent bonds, compounds
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the most important factor in determining whether a reaction will occur is the _____
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energy changes/flow of energy/activation
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matter is anything that has _____
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mass and volume
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what determines the properties of an element?
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the element's electrons
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How is an ionic bond formed between two atoms?
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An electrical force forms between oppositely charged ions.
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all atoms of the same substance have the same _____
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atomic number
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the basic unit of matter is the _____
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atom
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all atoms of the same substance have the same _____
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atomic number
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any spontaneous chemical reaction _____
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releases energy
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in the compound NaCl, the sodium and chlorine are held together by _____
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ionic bonds
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ionic bonds are _____
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the attraction between oppositely charged ions
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the smallest particle of a covalently bonded compound is a _____
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molecule
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_____ is the resulting structure of covalent bonds
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molecule
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smallest unit of most compounds
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molecule
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h2O is a _____
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formula
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symbol is used _____
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for only 1 element
ex: P, Na, etc. |
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formula is used for _____
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molecule (2 covalently bonded atoms)
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two or more _____ atoms are combined in _____ proportions in any _____
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different, definite, compound
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CO is a _____
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compound
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Cl is a _____
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symbol
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1H, 2H, 3H are _____
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isotopes (same atomic number, differently mass number)
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physical property
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doesn't change identity
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chemical property
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how they mix together/bond
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2H2O --> O2 + 2H2 is not a _____
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spontaneous reaction
(possible when there is an electrical charge_ |
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approximately _____ of the mass of an atom is in the _____
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99.9%, nucleus
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electrons compared to protons have _____ of mass
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1/1836
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the _____ and _____ of a compound are usually _____ from those of the elements from which it is formed
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physical, chemical properties, different
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stomach acid is _____,
oven cleaner is _____, |
acidic, basic
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_____ affect the reactions in _____ by changing the _____
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enzymes, living cells, speed of the reaction (increase/decrease)
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_____ affect chemical reactions by increasing the speed of _____
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catalysts, hemical reactions
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_____ have _____ nuclei and breakdown at a _____
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radioactive isotopes, unstable, constant rate of time
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how are isotopes identified?
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by their mass numbers
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what holds atoms in compounds together?
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chemical bonds
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_____ are the attractions between _____ regions of nearby _____
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van der waals forces, oppositely charged molecules
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when bond between atoms break, _____ is released
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break, energy, released
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