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44 Cards in this Set
- Front
- Back
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(T/F) Chemical changes are the result of chemical reactions.
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T
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(T/F) Chemical reactions involve the making and breaking of chemical bonds.
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T
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A __________ is a process by which atoms or groups of atoms are redistributed, resulting in a change in the molecular composition of substances.
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Chemical Reaction
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List 5 unique observations that point to a chemical reaction having taken place.
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1. A solid separates from a liquid
2. A gas is produced 3. The colors of the chemicals change permanently 4. the temperature of the substances changes 5. Light or sound is produced |
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Chemical _________ represent the chemical composition (makeup) of the substances.
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formulas
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Chemical _________ describe the changes that take place as the substances react.
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equations
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(T/F) A chemical formula specifies the number of each element present in a compound.
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T
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Consider C₁₂H₁₂O₆: How many total atoms are in this compound? How many hydrogen atoms are there? What is the ratio of carbon atoms to oxygen atoms?
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46 atoms; 22 hydrogen atoms; ratio of 1:1
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(T/F) C₆H₁₂O₆ is both the molecular formula for glucose and the empirical formula for glucose.
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F
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Chemists use oxidation numbers of the involved elements to predict chemical formulas.
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T
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________ tell how many electrons an element is likely to gain, lose, or share as it bonds to other atoms.
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Oxidation numbers
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Explain the "link" between oxidation numbers and the valence electrons for an atom.
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The are closely related, but oxidation numbers have a charge.
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The oxidation numbers for pure elements is _________.
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0
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The oxidation number of neutral substances that contain only one element (O₂, O₃, Cl₂, P₄, S₈, Al) is ______.
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0
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Oxidation numbers are derived from a knowledge of ________ in the periodic chart.
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families
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(T/F) Metals in groups IA, IIA, and IIIA have low electronegativites and thus lose electrons when combined with atoms having greater electronegativities.
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T
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(T/F) Metals are assigned positive oxidation numbers because they have low electronegativities and thus lose electrons when combined with atoms having greater electronegativities.
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T
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(T/F) Sodium, magnesium, iron and aluminum all have positive oxidation numbers.
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T
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(T/F) All nonmetals are assigned negative oxidation numbers.
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F
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The elements comprising the group assigned oxidation numbers of +1 are called __________.
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Alkali metals
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Aluminum has _____ valence electrons and is assigned an oxidation number of ________.
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3; +3
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Group ________ atoms are assigned an oxidation number of +2
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Group IIA
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Transition group metals generally have oxidation numbers of _________.
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+1 or +2
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Because the halogens have a great tendency to gain 1 electron to complete octets and thus become monoanions, halogens are assigned an oxidation number of ______.
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-1
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Oxygen usually has an oxidation number of ____.
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-2
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(T/F) The sum of the oxidation numbers in a neutral molecule must be zero.
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T
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(T/F) The sum of the oxidation numbers in a polyatomic anion must be zero.
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F
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Which statement is not accurate as applied to a chemical equation?
a. The products are placed to the left of the arrow. b. The reactants are placed to the left of the arrow. c. The arrow represents the direction in which the reaction proceeds. d. Atoms must be balanced on both sides of the arrow. |
A
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A compound that is composed of two different elements.
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Binary Compounds
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A group of several atoms that acts as a charged particle
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Polyatomic ions
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A number placed before a formula to balance an equation.
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Coefficient
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The "empirical formula" for an ionic solid
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Formula unit
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Symbols that indicate the number of electrons that an element gains or loses as it bonds.
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Oxidation numbers
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A shorthand method of expressing the makeup of a compound (pure substance).
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Chemical formula
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A small number placed beside the symbol of an element in a formula to indicate the number of atoms of that element contained in the compound represented by that formula.
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Subscript
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The chemical properties of the elements are periodic functions of their atomic numbers.
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Periodic law
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A substance (on the left hand side of the equation) that undergoes a chemical change.
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Reactants
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A substance (on the right hand side of the equation) that is produced by a chemical change.
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Products
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Bond that results from the attraction between cations and anions.
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Ionic bond
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Ionic attraction
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Electrostatic force
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The bond formed by the sharing of electrons
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Covalent bond
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Describe the changes that take place during a chemical reaction
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Chemical equations
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A covalent bond with a partial separation of charge: Bonds between atoms having an electronegativity difference greater than 0.5 and less than 2.
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Polyatomic ions
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An element that tends to give up electrons in chemical reactions
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Metals
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