Chemistry Chapter 2 (LearnSmart) Mid-Term
molecules
A molecular compound is composed of individual units called ___________.
neutral
A molecular compound is electrically _______.
hydrogen
An acid is a substance that yields ______ ions when dissolved in water.
protons; zero
An atom is composed of a very dense central nucleus containing _______, which are positively charged, and neutrons, which have _____ electrical charge.
array
An ionic compound consists of a three-dimensional _______ of ions.
anions and cations
An ionic compound is composed of which two species?
decays; radiation
An unstable nucleus exhibits radioactivity; it spontaneously disintegrates or _____ by emitting _______.
1. The metal sheet in this experiment emitted high-energy radiation consisting of neutral particles 2. A thin sheet of beryllium was bombarded with (a) particles 3. Chadwick discovered that atoms contain electrically neutral particles in addition to the protons and electrons
Describe Chadwick's experiment and discoveries.
1. Atoms of the same element are identical 2. Compounds result from the combination of a specific ratio of atoms of different elements 3. All matter consists of atoms
Describe Dalton's atomic theory.
1. A cathode ray consists of negatively charged particles 2. The discovery of cathode rays showed that an atom can be broken down into smaller particles
Describe cathode rays.
1. The second element is named with its root and the suffix -ide. 2. A Greek numerical prefix is used to indicate the number of atoms of each element in the compound. 3. The name of the first element remains unchanged, except for the addition of a prefix where appropriate.
Describe how to name a binary molecular compound.
1. For a monatomic anion, the element name is changed to end in -ide. 2. The cation is named first and the anion second.
Describe how to name an ionic compound.
1. Binary acids have the prefix hydro- to specify that they contain hydrogen 2. Acids are named differently depending on their physical state 3. Binary acids contain the nonmetal root and then the suffix -ic
Describe how to name binary acids.
1. A Greek prefix is used to indicate the number of H2O molecules per formula unit 2. A hydrate has a specific number of water molecules associated with each formula unit 3. Heating a hydrate can remove some or all of the water molecules
Describe hydrated ionic compounds.
1. Different compounds can have the same empirical formula 2. The empirical formula of a compound gives the relative numbers of atoms in a compound
Describe the empirical formula.
protons
Each element has a unique number of _________, which is called the atomic number.
the charge to mass ratio of an electron
From Millikan's charged oil drop experiments, what did he determine?
A given compound always contains a fixed ratio of its component elements.
How does Dalton's atomic theory account for the fact that different samples of the same compound always contain a fixed mass percentage of its component elements?
2
How many atoms does the Greek numerical prefix (di-) indicate?
7
How many atoms does the Greek numerical prefix (hepta-) indicate?
6
How many atoms does the Greek numerical prefix (hexa-) indicate?
1
How many atoms does the Greek numerical prefix (mono-) indicate?
5
How many atoms does the Greek numerical prefix (penta-) indicate?
ionic; ion
In the Stock system Roman numerals are used to name _______ compounds containing a metal that can form more than one _____.
neutral
Ionic compounds are electrically ______ overall.
mass
Isotopes are atoms of the same element that have the same atomic number but a different _______ number.
neutrons
Isotopes have the same number of protons but a different number of what?
created or destroyed; fixed
Mass is conserved in a chemical reaction. This observation is reflected in Dalton's postulate that atoms cannot be ____________, or changed into other types of atoms. Since each type of atom has its own _______ atomic mass, the total mass cannot change in a chemical reaction.
empirical
The chemical formula of an ionic compound is always written as the simplest or _______ formula.
atomic number
The elements are arranged in the periodic table in order of increasing _________.
periods
The horizontal columns of the table are called ________.
monatomic
The noble gases (Group 8A) exist in nature as single atoms, and for this reason they are called ______ gases.
zero
The sum of the charges on the cation and anion in each formula unit must be equal to _____.
groups
The vertical columns of the table are called ________.
electrons; negative
Thomson's experiments with cathode rays determined that atoms contained even smaller particles called ______, which have a ______ charge.
-ide
To name the anion, the root of the nonmetal name is added to the suffix ______.
dichlorine heptoxide
Use the nomenclature rules to name the molecular compound Cl2O7 correctly.
beta particles
What are known as electrons?
alpha particles
What are known as positively charged particles?
1. This experiment used (a) particles to probe atomic structure 2. An (a) particle was known at this time to be positively charged 3. The pathway followed by the (a) particles was tracked using a detecting screen.
What correctly describes Rutherford's experiment?
1. Ionic compounds are composed of cations and anions 2. The correct chemical formula for sodium chloride (table salt) is NaCl not Na+Cl. 3. The formula of an ionic compound is usually written as an empirical formula.
What correctly describes ionic compounds?
1. The mass of an electron is significantly smaller than the mass of a proton. 2. Protons are positively charged. 3. The electrons are located outside the nucleus of an atom
What correctly describes subatomic particles?
1. The atomic number is equal to the number of protons in the nucleus. 2. Each element has its own unique atomic number
What correctly describes the atomic number of an element?
with the root based on the number of carbon atoms followed by the suffix -ane
What describes how straight-chain alkanes are named?
1. Straight-chain alkanes are a class of hydrocarbons 2. Hydrocarbons are used as fuels 3. Hydrocarbons contain only carbon and hydrogen
What describes hydrocarbons?
1. Many molecular compounds are binary compounds. 2. The smallest unit of a molecular compound is called a molecule.
What describes molecular compounds?
1. The formulas of ionic compounds are usually empirical formulas 2. The sum of the charges of each ion that make up an ionic compound must be zero.
What describes the chemical formulas of ionic compounds?
1. The mass number of an element is given the symbol A. 2. The mass number is given by the sum of the protons and neutrons in the nucleus. 3. The mass number is often written as a left superscript next to the atomic symbol.
What describes the mass number of an element?
OH
What does a base produce when dissolved in water?
sodium (Na)
What element could reasonably be the cationic portion of an ionic compound?
alkaline earth metal
What group on the periodic table does Ca go in?
halogen
What group on the periodic table does Cl go in?
alkali metal
What group on the periodic table does Na go in?
noble gas
What group on the periodic table does Ne go in?
1. Ratio of elements in a compound 2. Types of elements present in a compound
What information is contained in a chemical formula?
1. Ca^2+ and 2F 2. Na+ and Br- 3. 2 Li+ and S^2-
What ion combinations will result in an ionic compound that has a balanced number of positive and negative charges?
ferrous
What is Fe^2+ named?
ferric
What is Fe^3+ named?
base
What is a substance that yields hydroxide ions (OH) when dissolved in water?
metalloid
What is an element that has properties between those of metals and nonmetals?
metal
What is an element that is a good conductor of heat and electricity, has a shiny surface, is malleable and ductile?
nonmetal
What is an element that is generally a gas or a dull brittle solid at room temperature, and is a poor conductor of heat and electricity?
Rbl
What is an example of a binary compound?
ZnSO4
What is an example of a ternary compound?
molecule
What is an independent structure consisting of two or more atoms chemically bonded together?
1. Isotopes have different numbers of neutrons. 2. Isotopes have similar chemical properties. 3. Isotopes of the same element have the same element symbols
What is correct about isotopes?
oxoacid
What is known as an acid that contains oxygen bonded to a central element?
cation
What is known as an ion with fewer electrons than its neutral atom?
anion
What is known as an ion with more electrons that its neutral atom?
positive
What is known as the charge of an ion with fewer electrons than its neutral atom?
negative
What is known as the charge of an ion with more electrons than its neutral atom?
Millikan's oil-drop experiments
What is known as the determination of the charge on a single electron?
Rutherford's gold-foil experiment
What is known as the discovery of the nucleus of the atom?
Thomson's experiments with cathode rays
What is known as the discovery that atoms can be divided into smaller particles?
molecular formula
What is known as the formula that gives the actual number of atoms of each element in a molecule?
empirical formula
What is known as the formula that gives the simplest whole number ratio of atoms of each element in a compound?
structural formula
What is known as the formula that shows the relative placement and connections of atoms in a molecule?
electron
What is known as the negatively charged particle?
proton
What is known as the positively charged particle found within the center of the atom?
nucleus
What is known as the small region that contains almost all of the mass of an atom?
neutron
What is known as the uncharged dense particle located in the center of the atom?
allotrope
What is one of two or more distinct forms of an element?
chloride
What is the anion formed by the element chlorine called?
fluoride
What is the anion formed by the element fluorine called?
atom
What is the basic unit of an element that can enter into chemical combination?
NaHCO3
What is the chemical formula for baking soda?
CaCO3
What is the chemical formula for chalk?
CO2
What is the chemical formula for dry ice?
NaCl
What is the chemical formula for table salt?
BaH2
What is the correct chemical formula for barium hydride?
SF4
What is the correct chemical formula for sulfur tetrafluoride?
Rb2SO4
What is the correct formula for rubidium sulfate?
N2O5
What is the correct molecular formula for dinitrogen pentoxide?
hydroiodic acid
What is the correct name for HI when dissolved in aqueous solution?
lithium sulfite
What is the correct name for the compound Li2SO3?
nitrogen dioxide
What is the correct name for the molecular compound NO2?
hypobromous acid
What is the correct name for the oxoacid HBrO?
lithium nitride
What is the correct name of the ionic compound Li3N?
O^2-
What is the correct symbol for the oxide anion, which has a charge of -2?
NH3
What is the molecular compound for ammonia?
CH4
What is the molecular compound for methane?
H20
What is the molecular compound for water?
Group 1A
What is the name of the group of alkali metals on the periodic table?
Group 2A
What is the name of the group of alkaline earth metals on the periodic table?
Group 7A
What is the name of the group of halogens on the periodic table?
Group 8A
What is the name of the group of noble gases on the periodic table?
chromium(III) chloride
What is the name of the ionic compound CrCl3?
-ic
What is the suffix of the metal cation with the higher charge?
-ous
What is the suffix of the metal cation with the lower charge?
1. Oxygen 2. Nitrogen 3. Fluorine
What nonmetals exist as diatomic molecules at room temperature?
1. An "anionic" portion derived from a polyatomic ion 2. A nonmetal as the "anionic" portion 3. One or more hydrogen atoms
What species can be found in the chemical formula of an acid?
law of definite proportions
What states that different samples of the same compound always contain its constituent elements in the same proportion by mass?
law of multiple proportions
What states that if two elements can combine to form more than one compound, the mass of one element that combine with a fixed mass of the other element are in ratios of small whole numbers?
law of conservation of mass
What states that matter can neither be created nor destroyed?
metals
What type of element is represented by the large green area to the left of the "stair step"?
metalloids
What type of element is represented by the narrow purple/gray strip located on both sides of the stair step?
nonmetals
What type of element is represented by the small blue area to the right of the "stair step"?
cation
When naming an ionic compound, the ______ is always named first.
gamma rays
uncharged
molecular
The _______ formula shows the exact number of atoms of each element in the smallest unit of a substance.
oxide
The anion O^2- is therefore named _______.
carbon
Organic compounds always contain _______ and hydrogen.
electrons
Since an atom is neutral, this number is also equal to the number of ________ present.
charge
The Roman numeral in the Stock system specifies the ________ on the metal.
mass, neutrons
The _____ number of an atom is equal to the sum of the protons and ______ in the nucleus of the atom.