Atoms, Ions, and Compounds

Atoms, Ions, and Compounds
Chapter 2 Atoms, Ions, and Compounds

Atoms, Molecultes,and Ions Topics
2-1 Early Ideas of Atomic Theory 2-2 Evolution of the Atomic Theory 2-3 Atomic Structure and Sympolism 2-4 Chemical Formulas 2-5 The Periodic Table 2-6 Molecular and Ionic Compounds 2-7 Chemical Nomenclature

The Composition of Compounds
The law of multiple proportions states that the masses of element Y that combine with a fixed mass of elements X to form two or more different compounds are in the ratios of small whole numbers. Examples: NO, NO2, N2O, N2O5, etc.

Atomic Structure J. J. Thomson discovered the subatomic particle know as the electron. Thomson used cathode ray tube.

Mass of An Electron Robert Millikan determined the mass of an electron with his oil-droplet experiment.

Thomson Model of the Atom
J. J. Thomson’s Plum-pudding model of the atom.

Radioactivity and the Nuclear Atom
HISTORY Henri Becquerel discovered that some samples produced invisible radiation. One type is a steam of beta () particles (high energy electrons). A second type consists of alpha () particles, which have a +2 charge and a mass equivalent to that of a helium nucleus.

Identification of Radiation

Penetrating Effects

Nuclear Chemistry Nuclear chemistry is the study of reactions that involve changes in the nuclei of atoms. Radioactive decay is the spontaneous disintegration of alpha, beta, and gamma particles.

Rutherford’s Experiment
Rutherford and two of his students bombarded a thin foil of gold with  particles to test Thomson’s model of the atom. Theory would predict that the  particles would travel through the foil without deflection, but the results didn’t confirm the model.

Rutherford’s Experiment

The Nuclear Atom The nucleus of an atom contains all the positive charge and nearly all the mass in an atom. The nucleus is about 1/10,000 the size of the atom. A proton is a positively charged subatomic particle present in the nucleus of an atom.

The Third Subatomic Particle
A neutron is an electrically neutral or uncharged subatomic particle found in the nucleus of an atom. Atomic Mass Units (amu) comprise a relative scale used to express the masses of atoms and subatomic particles. The scale is based on the definition that the mass of 1 atom of carbon with 6 protons and 6 neutrons in its nucleus is exactly 12 amu.

Aston’s Experiment Francis W. Aston built a postive-ray analyzer.
Data from neon gas samples demonstrated that two different kinds of atoms or isotopes existed. Isotopes are atoms of an element whose nuclei have the same number of protons but different numbers of neutrons.

Aston’s Positive-ray Analyzer

Symbols of Isotopes Each element consists of atoms with the same number of protons in the nucleus. This number is called atomic number (Z). Protons and neutrons in atomic nuclei are called nucleons. The mass number (A) is the total number nucleons in one atom of an element.

Writing the Symbol of an Isotope
X A Z A is the mass number Z is the atomic number X is the atomic symbol

Average Atomic Masses A mass spectrometer is an instrument that measures precise masses and relative amounts of ions of atoms and molecule. The natural abundance of an isotope is its relative proportion among all the isotopes found a natural sample. The average atomic mass of an element is calculated by multiplying the natural abundance of each isotope by its exact mass in atomic mass units and then summing these products.

Example Neon is found in three isotopes in nature. Isotope Mass (amu)
Natural abundance (%) Neon-20 Neon-21 0.2696 Neon-22 9.2465

Example Neon is found in three isotopes in nature. Isotope Mass (amu)
Natural abundance (%) Neon-20 Neon-21 0.2696 Neon-22 9.2465 x = amu x = amu x = amu amu

Mendeleev’s Periodic Table
Dmitrii I. Mendeleev arranged elements in the periodic table by their chemical and physical properties. He left open spaces in his periodic table to account for elements not yet discovered.

The Modern Periodic Table
The modern periodic table is also based on a classification of elements in terms of their physical and chemical properties. The horizontal rows are called periods. Columns contain elements of the same family or group. Transition metals are the elements in group 3 through 12 in the periodic table.

Groups of Elements Group 1 contains the alkali metals.
Group 2 contains the alkaline earth metals. Group 17 contains the halogens. Group 18 contains the Noble gases.

Broad Categories of Elements
Metals are elements on the left-hand side of the table. Metals are shiny solids that conduct heat and electricity well and are malleable and ductile. Nonmetals have properties opposite to those of the metals and are on the right side of table Metalloids are the elements between the metals and nonmetals.

Continued Main group elements or representative elements are the elements in groups 1,2 and 13 through 18. The noble gases are the elements in Group 18.

Kinds of Compounds Molecular Compounds are composed of atoms held together by covalent bonds. Covalent bonds are shared pairs of electrons that chemically bond atoms together. Ionic Compounds are composed of positively and negatively charged ions that are held together by electrostatic attraction. Ions with negative charge are called anions. Ions with positive charge are called cations.

Continued Molecular compounds are made of nonmetals
Ionic compounds are made of a metal and a nonmetal. Metal form cations and nonmetals form anions.

Ionic Compounds Crystal Lattice of NaCl
Ionic compounds do not exist as discrete molecules. Instead they exist as crystals where ions of opposite charges occupy positions known as lattice sites. Ions combine in the ratio that results in zero charge to form ionic compounds. Since there is almost and infinite number of ions in a crystal lattice, then the smallest ratio, called the formula unit, is used to describe an ionic compound Crystal Lattice of NaCl

Terms Molecular formulas describe the exact number and type of atoms present in one molecule of a compound. An empirical formula gives the simplest whole-number ratio of elements in a compound. The formula unit of an ionic compound is the smallest electrically neutral unit within the crystal of the compound.

Common Oxidation States
1+ 2+ 3- 2- 1- 3+ 4+

Common Oxidation States
By Group Number

Sample Problem An ion with a 3+ charge contains 23 electrons. Which ion is it?

Sample Problem An ion with a 3+ charge contains 23 electrons. Which ion is it? Fe3+ A certain ion X+ contains 54 electrons and 78 neutrons. What is the mass number of this ion?

Sample Problem An ion with a 3+ charge contains 23 electrons. Which ion is it? Fe3+ A certain ion X+ contains 54 electrons and 78 neutrons. What is the mass number of this ion? 133

Ionic Compounds High melting points Conduct electricity
Ions combine to form ionic compounds. The simplest ratio between the ions is called the empirical formula or a formula unit. Properties of ionic compounds High melting points Conduct electricity If melted If dissolved in water Ionic compounds are electrically neutral. The charges on the anions and cations in the compound must sum to zero.

Ionic Compounds Crystal Lattice of NaCl
Ionic compounds do not exist as discrete molecules. Instead they exist as crystals where ions of opposite charges occupy positions known as lattice sites. Ions combine in the ratio that results in zero charge to form ionic compounds. Which ions are the smaller ones? Crystal Lattice of NaCl

Formula Writing Rules Examples
Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers (O.N. = P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus

Formula Writing Rules Examples Na O Na N Ca O Ca P
Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O Na N Ca O Ca P

Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O 1+ Na N 3- Ca O Ca P

Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O 1+ Na N 3- 2+ Ca O 2- Ca P

Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O 1+ Na N 3- 2+ Ca O 2- Ca 2+ P 3-

Formula Writing Rules Examples Na O Na O Na N Ca O Ca P
Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O ≡ Na O 2 1+ Na N 3- 2+ Ca O 2- Ca 2+ P 3-

Formula Writing Rules Examples Na O Na O Na N Na N Ca O Ca P
Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O Na O ≡ 2 1+ Na N 3- Na ≡ N 3 2+ Ca O 2- Ca 2+ P 3-

Formula Writing Rules Examples Na O Na O Na N Na N Ca O Ca O Ca O Ca P
Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O Na O ≡ 2 1+ Na N 3- ≡ Na N 3 2+ Ca O 2- Ca O ≡ Ca O 2 2 reduced Ca 2+ P 3-

Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O Na O ≡ 2 1+ Na N 3- Na N ≡ 3 2+ Ca O 2- Ca O Ca O ≡ 2 2 reduced Ca 2+ P 3-

Step 1 Write the symbols of the elements. Step 2 Assign oxidation numbers O.N. = (P – e) Step 3 Slide with Clyde! (number only) Step 4 Reduce if the compound is ionic Examples Write formulas for the following two elements Sodium and oxygen Sodium and nitrogen Calcium and oxygen Calcium and phosphorus 1+ Na 2- O ≡ Na O 2 1+ Na N 3- Na N ≡ 3 2+ Ca O 2- Ca O ≡ Ca O 2 2 reduced Ca 2+ P 3- Ca P ≡ 3 2

NOMENCLATURE I. Binary Ionic compounds
Binary means two different elements Ionic means metal and nonmetal Step 1 First give the name of the metal, followed by the nonmetal name using the “ide” suffix. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to to describe the charge of the metal. Except Ag, Zn,and Al Examples NaCl Al2O3 FeCl2 FeCl3

Binary means two different elements Ionic means metal and nonmetal Step 1 First give the name of the metal, followed by the nonmetal name using the “ide” suffix. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to to describe the charge of the metal. Except Ag, Zn,and Al Examples NaCl Sodium chloride Al2O3 FeCl2 FeCl3

Binary means two different elements Ionic means metal and nonmetal Step 1 First give the name of the metal, followed by the nonmetal name using the “ide” suffix. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to to describe the charge of the metal. Except Ag, Zn,and Al Examples NaCl Sodium chloride Al2O3 Aluminum oxide FeCl2 FeCl3

Binary means two different elements Ionic means metal and nonmetal Step 1 First give the name of the metal, followed by the nonmetal name using the “ide” suffix. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to to describe the charge of the metal. Except Ag, Zn,and Al Examples NaCl Sodium chloride Al2O3 Aluminum oxide FeCl2 Iron(II) chloride FeCl3

Binary means two different elements Ionic means metal and nonmetal Step 1 First give the name of the metal, followed by the nonmetal name using the “ide” suffix. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to to describe the charge of the metal. Except Ag, Zn,and Al Examples NaCl Sodium chloride Al2O3 Aluminum oxide FeCl2 Iron(II) chloride FeCl3 iron(III) chloride

Nonbinary means more than two different elements
II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOH Fe(NO3)3 Zn(C2H3O2)2 Fe(SO4)2

Memorized Polyatomic Ion List
Formula Name NH4+ Ammonium O22- Peroxide C2H3O2- Acetate NO3- Nitrate CO32- Carbonate NO2- Nitrite HCO31- Hydorgen carbonate SO42- Sulfate ClO4- Perchlorate SO32- Sulfite ClO3- Chlorate PO43- Phosphate ClO2- Chlorite PO33- Phosphite ClO- Hypochlorite CrO42- Chromate CN- Cyanide Cr2O72- Dichromate MnO4- Permanganate OH- Hydroxide C2O42- Oxalate

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 CO If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOH Sodium hydroxide Fe(NO3)3 Zn(C2H3O2)2 Fe(SO4)2

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOH Sodium hydroxide Fe(NO3)3 Iron(III) nitrate Zn(C2H3O2)2 FeSO4

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOH Sodium hydroxide Fe(NO3)3 Iron(III) nitrate Zn(C2H3O2)2 FeSO4 Iron(II) sulfate

II. Nonbinary Ionic compounds Nonbinary means more than two different elements Step 1 First give the name of the metal, followed by the memorized polyatomic ion name. Step 2 If the metal is to the right of group IIA, then a Roman numeral is used after the metal to describe the charge of the metal. Except Ag, Zn, and Al. Examples NaOH Sodium hydroxide Fe(NO3)3 Iron(III) nitrate Zn(C2H3O2)2 FeSO4 Zinc acetate Iron(II) sulfate

III. Binary molecular Compounds
Molecular means nonmetals Step 1 First give the name of the first nonmetal, followed by the nonmetal name using the “ide” suffix. Step 2 Give each nonmetal a Latin prefix describing the number of atoms present in the compound. Examples CO CO2 P2O5 CCl4

You will need to learn the Greek numerical prefixes (Table 4.6):
Number Prefix 1 Mono-* 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- *Note 1 Compound names never start with mono Note 2 When adding a prefix two vowls cannot next to each other

III. Binary Molecular Compounds
Molecular means nonmetals Step 1 First give the name of the first nonmetal, followed by the nonmetal name using the “ide” suffix. Step 2 Give each nonmetal a Latin prefix describing the number of atoms present in the compound. Examples CO Carbon monoxide CO2 P2O5 CCl4

III. Binary Molecular Compounds
Molecular means nonmetals Step 1 First give the name of the first nonmetal, followed by the nonmetal name using the “ide” suffix. Step 2 Give each nonmetal a Latin prefix describing the number of atoms present in the compound. Examples CO Carbon monoxide CO2 Carbon dioxide P2O5 CCl4

II. Binary Ionic molecular
Molecular means combination of nonmetals Step 1 First give the name of the first nonmetal, followed by the nonmetal name using the “ide” suffix. Step 2 Give each nonmetal a Latin prefix describing the number of atoms present in the compound. Examples CO Carbon monoxide CO2 Carbon dioxide P2O5 Diphosphorus Pentoxide CCl4

II. Binary Ionic molecular
Molecular means combination of nonmetals Step 1 First give the name of the first nonmetal, followed by the nonmetal name using the “ide” suffix. Step 2 Give each nonmetal a Latin prefix describing the number of atoms present in the compound. Examples CO Carbon monoxide CO2 Carbon dioxide P2O5 Diphosphorus Pentoxide CCl4 Carbon tetrachloride

III. Nonbinary Molecular Compounds
Note: Do not use Latin prefixes Step 1 Write down the memorized polyatomic ions present in the compound. Step 2 Look to see if any monatomic ions are present. If so, then cations use the normal name. If it is an anion, then its name comes last with the “ide” suffix. Examples NH4Cl NH4OH

Note: Do not use Latin prefixes Step 1 Write down the memorized polyatomic ions present in the compound. Step 2 Look to see if any monatomic ions are present. If so, then cations use the normal name. If it is an anion, then its name comes last with the “ide” suffix. Examples NH4Cl Ammonium chloride NH4OH

Note: Do not use Latin prefixes Step 1 Write down the memorized polyatomic ions present in the compound. Step 2 Look to see if any monatomic ions are present. If so, then cations use the normal name. If it is an anion, then its name comes last with the “ide” suffix. Examples NH4Cl Ammonium chloride NH4OH Ammonium hydroxide

Compounds that Start with Hydrogen
Case 1 If the anion ends in “ide” and it is aqueous, then use the prefix hydro and suffix “ic acid” Case 2 If the anion ends in “ate” then drop it and add the suffix “ic acid” Case 3 If the anion ends in “ite” then drop it and add the suffix “ous acid” Case 4 If the anion ends in” ide” and is a gas, or liquid, then leave the name and do not use Latin prefiex

Examples Anion Name Compound Name HCl (aq) Chloride HNO3 HNO2 H2O (l) HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 HNO2 H2O (l) HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate HNO2 H2O (l) HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate Nitric acid HNO2 H2O (l) HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate Nitric acid HNO2 Nitrite H2O (l) HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate Nitric acid HNO2 Nitrite Nitrous acid H2O (l) HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate Nitric acid HNO2 Nitrite Nitrous acid Oxide H2O (l) HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate Nitric acid HNO2 Nitrite Nitrous acid Oxide H2O (l) Hydrogen oxide HCl (g)

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate Nitric acid HNO2 Nitrite Nitrous acid Oxide H2O (l) Hydrogen oxide HCl (g) Chloride

Examples Anion Name Compound Name HCl (aq) Chloride Hydrochloric acid HNO3 Nitrate Nitric acid HNO2 Nitrite Nitrous acid Oxide H2O (l) Hydrogen oxide HCl (g) Chloride Hydrogen chloride

Oxy Anions & Related Acids
Anion Anion Name Acid Acid Name ClO- Hypochlorite HClO Hypochlorous acid ClO2- Chlorite HClO2 Chlorous acid ClO3- Chlorate HClO3 Chloric acid ClO4- Perchlorate HClO4 Perchloric acid

Practice Write the names or chemical formulas for the following compounds. Cr(ClO4)3 NH4NO3 Lithium bicarbonate Calcium hypobromite

Practice Write the names or chemical formulas for the following compounds. Cr(ClO4)3 NH4NO3 Lithium bicarbonate Calcium hypobromite Chromium(III) perchlorate

Practice Write the names or chemical formulas for the following compounds. Cr(ClO4)3 NH4NO3 Lithium bicarbonate Calcium hypobromite Chromium(III) perchlorate Ammonium nitrate

Practice Write the names or chemical formulas for the following compounds. Cr(ClO4)3 NH4NO3 Lithium bicarbonate Calcium hypobromite Chromium(III) perchlorate Ammonium nitrate LiHCO3

Practice Write the names or chemical formulas for the following compounds. Cr(ClO4)3 NH4NO3 Lithium bicarbonate Calcium hypobromite Chromium(III) perchlorate Ammonium nitrate LiHCO3 Ca(BrO)2

The End Ch #2 Atoms and Elements

Atoms, Ions, and Compounds

Similar presentations

Presentation on theme: "Atoms, Ions, and Compounds"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Atoms, Ions, and Compounds

Similar presentations

Presentation on theme: "Atoms, Ions, and Compounds"— Presentation transcript:

Similar presentations

About project

Feedback