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.