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Chemistry flashcards
Chemistry unit flash cards for extra credit
| Question | Answer |
|---|---|
| What is the definition of atomic symbol? | Shorthand method for indicating the name of an element |
| What is the definition of atom? | The smallest particle of an element that retains the element’s properties |
| What is the definition of nucleus? | Positively charged center of the atom |
| What is the definition of proton? | Particles in the nucleus with a charge of +1 |
| What is the definition of neutron? | Particles in the nucleus with no charge |
| What is the definition of electron? | Particles around the nucleus with a charge of -1 |
| What are protons and neutrons made of? | Quarks |
| What were used to search for quarks? | Particle accelerators |
| Who was Democritus? | Greek philosopher around 400 B.C. who proposed the idea that atoms make up all matter |
| Who was Aristotle? | Greek philosopher who disputed Democritus’s idea and proposed matter was uniform throughout and made of 5 elements:Water, Earth, Air, Fire, Aether. His incorrect idea was accepted for about 2,000 years. |
| What is Dalton’s Atomic Theory? | Matter is made of tiny particles called atoms. Atoms are indivisible. Atoms of a given element are all the same. Atoms of an element are different than atoms of other elements. Different atoms combine in ratios to form compounds. |
| What is Thomson's Model? | Thomson discovered the electron and proposed that electrons floated around in atoms like plums in plum pudding |
| What year did Thomson discover this model? | 1904 |
| What is the Rutherford Model? | Rutherford proposed that all the positive charge of an atom was concentrated in the nucleus and was surrounded by electrons with empty space in between. |
| What year did Rutherford propose this model? | 1911 |
| What is the Bohr Model? | Bohr proposed that electrons travel in fixed orbits like planets orbiting the sun. |
| What year did Bohr propose this model? | 1913 |
| What is the Electron Cloud Model? | Present model in which electrons travel in unpredictable paths around the nucleus (the electron cloud) |
| What is the definition of atomic number? | The number of protons in an atom’s nucleus (also equal to number of electrons) |
| What is the definition of mass number? | Sum of the number of protons and neutrons in the nucleus of an atom |
| What is the definition of Isotopes? | Atoms of the same element that have different numbers of neutrons |
| What is the definition of half-life? | Amount it takes for half of a sample of an isotope to break down into other elements |
| What is the definition of carbon dating? | Using the decay of C-14 to determine the age of organic substances |
| What is the definition of average atomic mass? | The weighted average mass of all naturally occurring isotopes of an element |
| What do electrons occupy different energy levels in? | An atom |
| What is the definition of valence electrons? | Electrons in the outermost sublevel of an atom |
| Who is Dmitri Mendeleev? | Man who developed the 1st periodic table in late 1800s, based position of elements on atomic mass, and used gaps in table to and properties of surrounding elements to predict properties of unknown elements |
| Who is Henry G.J. Mosely? | Man who developed the modern periodic table in 1913, based position of elements on atomic number, and properties of elements fit into groups better based on atomic # |
| What is the definition of groups? | Vertical columns on periodic table |
| What is another name for groups? | Families |
| How many groups are in the periodic table? | 18 |
| What is the definition of an electron dot diagram? | The symbol of an element surrounded by dots to represent valence electrons |
| What is the definition of periods? | Rows on the periodic table |
| What is the definition of metalloids? | Elements along the stair step line of the periodic table that have properties that lie somewhere between metals and nonmetals |
| What is the definition of diatomic elements? | Elements in which two atoms of the same element are almost always bonded together |
| What is the definition of chemical formula? | Shows what elements a compound contains and the ratio of the elements |
| What does a subscript do? | Indicates number of atoms of element in compound |
| What is the definition of a chemical bond? | Force that holds atoms together in a compound |
| What is the definition of an ionic bond? | Type of bond formed when electrons are transferred between atoms, creating opposite charges that attract |
| What does an ionic bond usually occur between? | Metals and nonmetals |
| What is the definition of an ion? | A charged particle that has either more or fewer electrons than protons |
| What is the definition of a positive ion? | More protons than electrons (has lost electrons) |
| What is another name for a positive ion? | Cation |
| What is the definition of a negative ion? | More electrons than protons (gained electrons) |
| What is another name for a negative ion? | Anion |
| What is the definition of an oxidation number? | Combining ability of an element (charge on ion when in an ionic compound) |
| What is the definition of a covalent bond? | The attraction that forms between atoms when they share electrons (nonmetals) |
| What is the definition of a noncovalent bond? | Electrons are shared equally by both atoms |
| What is the definition of a polar covalent bond? | Electrons are shared unequally by atoms |
| What is the definition of a polar molecule? | The unequal sharing of electrons results in a slightly positive end and a slightly negative end to the molecule |
| What is the definition of a nonpolar molecule? | Molecule that does not have oppositely charged ends |
| What is the definition of a type 1 binary compound? | Two elements: A-group metal + nonmetal |
| What are the steps to naming a type 1 binary compound? | Write the name of the metal, write the name of the nonmetal, and add -ide to the root of the nonmetal. |
| What is the definition of a type 2 binary compound? | Two elements: Variable charge metal + nonmetal |
| What are the steps to naming a type 2 binary compound? | Determine which ions are present, use charge on nonmetal to determine charge on metal, write the name of the metal ion with Roman Numerals, write the name of the nonmetal, and add -ide to the root of the nonmetal. |
| What is the definition of a type 3 binary compound? | Molecule formed when two nonmetals bond together |
| What are the steps to naming a type 3 binary compound? | Write the name of the 1st nonmetal in the formula, write the name of the 2nd nonmetal in the formula, change the ending to -ide, and add required prefixes to show how many atoms of each element are in a molecule |
| What is the definition of a polyatomic ion? | Formed from a group of atoms that combine together to form a single ion |
| What are the steps for writing formulas? | Indicate which ions are present, treat polyatomic ions as single ions (don’t change subscripts, etc.), put ions together in a formula so that charges balance (just like type 1 binary compounds) |
| What are the steps for writing names? | Indicate which ions are present in the formula, write the names of the ions, don’t forget to add Roman Numerals if the metal ion can have multiple charges |
| What is the definition of hydrate? | A compound that has water molecules as part of its structure |
| What is the definition of a chemical reaction? | Change in which one or more substances are converted into new substances |
| What is the definition of reactants? | Starting substances |
| What is the definition of products? | New substances produced |
| What is the definition of a chemical equation? | A way to describe a chemical reaction using chemical formulas and other symbols |
| What is the definition of coefficients? | Represent the number of units of each substance taking part in the reaction |
| What is the definition of subscripts? | Represent the number of each element or polyatomic ion in a unit of the compound |
| What is the definition of a balanced chemical equation? | Chemical equation with the same number of atoms of each element on both sides of the arrow |
| What is the definition of a combustion reaction? | Occurs when a substance reacts with oxygen to produce energy in the form of heat and light |
| What is the definition of a synthesis reaction? | Two or more substances combine together to form another substance |
| What is the definition of a decomposition reaction? | Occurs when one substance breaks down into two or more substances |
| What is the definition of a single-displacement reaction? | One element replaces another in a compound |
| What is the definition of a double-displacement reaction? | The positive ion of one compound replaces the positive ion of the other to form two new compounds |
| What is the definition of an exergonic reaction? | Chemical reaction that releases energy |
| What is the definition of an exothermic reaction? | Exergonic reaction in which thermal energy is primarily released |
| What is the definition of an endergonic reaction? | Chemical reaction that absorbs energy |
| What is the definition of an endothermic reaction? | A reaction that absorbs thermal energy to keep going |
| What is the definition of reaction rate? | Rate at which reactants change into products |
| What is the definition of a catalyst? | A substance that speeds up a chemical reaction without being permanently changed itself |
| What is the definition of enzyme? | Biological catalyst |
| What is the definition of an inhibitor? | Substances used to slow down the rates of chemical reactions or prevent a reaction from happening at all (food preservatives) |
| What is the definition of an equilibrium? | A state in which forward and reverse reactions or processes proceed at equal rates |