Ch.2 - Atoms & ElementsSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Jules Bruno

The Periodic Table is a listing of the elements in order of increasing atomic number and atomic mass. Its organization relates different elements by their chemical compositions and properties. 



Major Classification Types of the Period Table

The three major classifications in the periodic table include metals, non-metals and metalloids. 

Major-Element-ClassificationsMajor Element Classifications

Metals – comprise a majority of the elements on the periodic table. 

They are characterized as having luster (shininess), being good thermal and electrical conductors, being malleable and opaque, while having ductility and being solids at room temperature. 

Free Electrons on Metal Surfaces

Non-Metals – constitute the second largest classification for elements of the periodic table. 

They are characterized as having little to no luster (shininess), being poor thermal and electrical conductors, being brittle and transparent, while having no ductility and representing all phases at room temperature. 

Three-Phases-MatterThree Phases of Matter

Metalloids – constitute the smallest classification for elements on the periodic table. 

They share some of the characteristics of both metals and non-metals. Because of this hybrid classification they are sometimes called “semi-metals” or “semi-conductors.”

Group Classifications of the Period Table

Beyond the major classifications of the elements we can further divide them into groups or families

The Main Groups 1 - 8 or Group A Elements are the Alkali Metals, Alkaline Earth Metals or Rare Earth Metals, Pnictogens, Chalcogens, Halogens, Noble Gases or Inert Noble Gases. 

The remaining elements or Group B Elements are the Transition Metals and Inner Transition Metals, of which are further divided into Lanthanides and Actinides.   

Groups-of-the-Periodic-TableGroups of the Periodic Table

Elements, Symbols, & Beyond

From constant exposure to the elements of the periodic table you will find yourself memorizing 20 elements then 30 elements to 50 elements and beyond. 

Once you’ve memorized the periods, groups, and names of elements you will take a look at the orbital structure of elements when discussing isotopes, and the subatomic particles of protons, neutrons and electrons

Eventually you will begin doing calculations involving the elements’ moles and mass, their periodic trends (electronegativity, van der Waals forces, electron shells), their charges, and electron configurations (valence electrons, ground state, excited state). 


Jules Bruno

Jules felt a void in his life after his English degree from Duke, so he started tutoring in 2007 and got a B.S. in Chemistry from FIU. He’s exceptionally skilled at making concepts dead simple and helping students in covalent bonds of knowledge.


Additional Problems
List the monatomic ions that the elements below are expected to form when they are incorporated into an ionic compound (give the symbol and the charge).             A)  sulfur         ____________ B)  lithium       ____________ C)  barium       ____________ D)  chlorine     ____________
What is the name of the elements in Group 2A of the periodic table? A. Transition metals B. Alkali earth metals C. Alkali metals D. Halogens
Which of the following elements does NOT have a symbol taken from a LATIN name? (A) iron (B) copper (C) sodium (D) potassium (E) phosphorus
What is the name of the element that has atomic number 59? a) Princeium b) Promethium c) Praeseodymium d) Proctorium e) Protactinium
Which of the following is true? A) Copper (Cu) is a main group element. B) Tellurium (Te) is a transition metal. C) Germanium (Ge) is a metalloid. D) Halogens are unreactive.
If aluminum and sulfur formed ions, what would be their charges, respectively? A) 2+, 2- B) 3-, 1- C) 3+, 2-  D) 1+, 1-
A food that has substantial amounts of compounds that have sulfur in them is: a. broccoli b. blueberries c. spinach d. cereal e. garlic
Which of the following might form a  -2 anion? a. Na b. Se c. Mg d. Si e. P
Which of the following elements are all metalloids?   a. Si, Ge, Po b. Al, Si, P c.P, As, Sb d. Sn, Sb, Te e. Al, Ga, In
What type of ions would be formed by potassium, aluminum and oxygen atoms, respectively? (A) P+, Al3+, O2- (B) K+, Al3+, O2- (C) K+, Al+, O6+ (D) K+, Al5-, O2- (E) K-, Al3-, O2+
Which is the chemical symbol for silicon?   a. S b. Si c. Sn d. Se e. None of the given answers.
The element with the symbol Y was named after a village in Sweden that has a quarry which has yielded many unusual metals. That is the name of this element?   a. Ytterbium b. Yakim c. Yttrium d. Yahbini e. Yardley
Ions differ in the number of A) electrons. B) neutrons. C) protons. D) neutrons and protons. E) electrons and protons.
What is the name of the element that has the symbol Ge? a. Gellium b. Gelfur c. Germanium d.Geraldium e. Georgium
Which of the following does NOT describe a metal? A) good conductor of heat B) good conductor of electricity C) tends to gain electrons D) forms ionic compounds with nonmetals E) found on the left side of the periodic table.
Which of the following elements is NOT correctly matched with its symbol? (A) sodium is Na (B) phosphorus is P (C) chlorine is Cl (D) carbon is C (E) neon is N
Identify the group or family to which each of the following elements belongs by placing the letter corresponding to the group in the blank to the left of the element.             _____ potassium                              A.  Halogen             _____ fluorine                                   B.  Transition metal             _____ magnesium                            C.  Alkali metal             _____ nickel                                      D.  Alkaline earth metal
Which of the following statements is/are correct? i. Au, Pb and Na are the symbols for gold, lead and sodium ii. K, S and Mn are the symbols for potassium, sulfur and magnesium iii. W, Ag and Ti are the symbols for tungsten, silver and titanium a. ii only b. iii only c. i and ii d. i and iii e. ii and iii
Which atom is most likely to form only a 2+ ion? a. iron b. barium c. aluminum d. copper e. fluorine  
Which of the following is a metal? a. Rb b. At c. Sb d. Ge e. Si
Which ions should be formed by magnesium, nitrogen, and chlorine, respectively? (A) Mg2+, N3-, Cl- (B) Mn7+, N3-, C4+ (C) Mg2+, N5+, Cl- (D) Mg+, N5+, C4+ (E) Mg+, N3-, Cl-
Predict the charge of the ion formed by each element.  a. Mg b. N c. F d. Na 
All the following elements exist as diatomic gases at room temperature and atmospheric pressure except H Cl N Ar O
Write the symbol for each element and classify it as a metal, nonmetal or metalloid. a. gold b. fluorine c. sodium d. tin e. argon
Which one of the following does not occur as diatomic molecules in elemental form? A) flourine B) nitrogen C) selenium D) hydrogen E) oxygen
Which of the following is a molecular element? A) Mg B) Ar C) Xe D) I E) Li
Which of the following statements is NOT true? A. Bromine is a diatomic element B. Antimony is a metalloid C. Scandium is an alkaline earth metal D. Neodynium is an inner transition metal
Which diagram(s) best characterize(s) an element? 1. I only 2. III and IV only 3. II only  4. I and II only
Which statement best reflects the organization of the modern periodic table? a) Elements are always arranged in order of increasing atomic weights. b) Metallic properties increase going from bottom to top in a family of elements. c) Nonmetallic properties tend to predominate for elements at the far right portion of the table. d) Each transition element is placed in the column of the main group element that it most closely resembles.
Match the following. i) oxygen ii) chlorine iii) neon iv) calcium v) iodine A) Ca(s)     B) Cl 2(g)     C) Cl(g)     D) Ne(g)     E) O(g)     F) Ca2(g)     G) Ne2(g)     H) O2(g)     I) I (g)     J) I 2(s)  
Which of the following characteristics are true of nonmetals?             I. good thermal and electrical conductors II. good thermal and electrical insulators III. readily lose electrons IV. readily gain electrons
The names of the elements whose symbols are Si, P, Mn, and S are, respectively, a. silicon, potassium, manganese, and sulfur. b. silver, phosphorus, magnesium, and sodium. c. silicon, potassium, magnesium, and sulfur. d. silver, potassium, manganese, and sodium. e. silicon, phosphorus, manganese, and sulfur.
Beryllium is an ____ and silver is a ____. A. alkaline earth metal; halogen B. alkali metal; nonmetal C. alkali metal; halogen D. alkali metal; transition metal E. alkaline earth metal; transition metal
Which of the following is not a correct name, symbol combination? a. calcium, Ca b. sodium, Na c. mercury, Hg d. uranium, U e. fluorine, FL
Write the formula and the phase for the following elements. a) Chlorine     b) Argon     c) Bromine     d) Zinc     
Classify each of the following elements into one or more of the given categories: A. Alkali Metal     B. Alkaline Earth Metal     C. Pnictogen     D. Chalcogen     E. Halogen     F. Noble Gas     G. Transition Metal     H. Inner Transition Metal     I. Representative Element     J. Lanthanide     K. Actinide 1) Br   2) Ca   3) H   4) No   5) Mn   6) P
Elements in the same group of the periodic table typically have_______. a. similar mass numbers b. similar physical properties only c. similar chemical properties only d. similar atomic masses. e. similar physical and chemical properties.
Which one of the following atoms has the least tendency to gain another electron? a) Neon b) Oxygen c) Chlorine d) Sodium e) Hydrogen
Which one of the following is an unreactive nonmetal? a. xenon b. nitrogen c. calcium d. zinc e. bromine
Identify the element from the given information. a) Alkaline earth metal in the 3rd period: ____________ b) Transition metal in the 5th period that has similar chemical properties to chromium: ____________ c) Metalloid that is a chalogen: ____________ d) Inner transition metal in the 6th period that has the greatest atomic mass: ____________ e) Representative element that is not diatomic in the 3rd period that assumes the shape and volume of the container that it is in: ____________ f) Halogen that has the smallest atomic number: ____________
How many of these elements are nonmetals?         Na         Cl         C         Fe         Rb         O         F         Au         P   a. 1 b. 2 c. 3 d. 4 e. 5
From what you know about ion formation and the periodic table, which ion would be unlikely to occur? a. Rb + b. Ca 2+ c. Al 3+ d. Na 2+ e. All of these ions are common ions.
Using the periodic table below, which of the following statements is   INCORRECT?
Which of the following is a compound? A. Hydrogen B. Water C. Helium D. Seawater E. Magnesium 
In reactions to form ionic compounds, metals generally 1. lose electrons. 2. become non-metals. 3. do not react. 4. gain electrons
Which pair of elements do you expect to be most similar?  Why? a) N, O           b) Ti, Ga                c) Li, Na     d) Ge, As       e) Ar, Br
Which of the following elements is an alkaline earth metal? a. Cs b. Cu c. Mg d. Ti e. Br
Which of the following does NOT describe a metal? A) Found on the left side of the periodic table. B) Good conductor of heat. C) Form ionic compounds with nonmetals. D) Good conductor of electricity. E) Tend to gain electrons.
A homonuclear diatomic molecule is a molecule composed of three atoms of the same element. 1) True 2) False
What is the common ion formed by nitrogen. 
Identify the group or family to which each of the following elements belongs by placing the letter corresponding to the group in the blank to the left of the element.   _____ potassium                              A.  Halogen  _____ fluorine                                  B.  Transition metal  _____ magnesium                           C.  Alkali metal  _____ nickel                                     D.  Alkaline earth metal
Metals and nonmetals can react with each other to form ions. Complete these statements.A potassium atom gains or loses (electrons/protons/neutrons) and forms how many ion?A sulfur atom gains or loses (electrons/protons/neutrons) and forms how many ion?
Which of the following elements is a  metalloid?  a) Ar b) As c) Be d) Cr e) Pb
Which of the following is an atomic element? A) calcium      B) chlorine      C) oxygen       D) hydrogen    E) nitrogen 
When the elements barium and phosphorus form ions, what are their charges, respectively? A) 2+, 3- B) 3+, 2- C) 3+, 3- D) 1+, 1-
Which of the following is an atomic element? A) Br B) Mg C) O D) H E) N
Which of the following shows a metal, nonmetal, and metalloid, respectively? A) Sc, B, Si B) Al, H, Si C) As, Ge, Ga D) Zr, Ar, Pb
For each of the following atomic numbers, use the periodic table to write the formula (including the charge) for the simple ion that the element is most likely to form in ionic compounds.a. 13
Give the nuclear symbol for the isotope of beryllium for which A = 10?
For the following element, write its chemical symbol, determine the name of the group to which it belongs , and indicate whether it is a metal, metalloid, or nonmetal: (a) potassium
For the following element, write its chemical symbol, determine the name of the group to which it belongs , and indicate whether it is a metal, metalloid, or nonmetal: (b) iodine
Lithium belongs to the _______ group of the periodic table. a) halogen b) alkaline earth metal c) noble gas d) alkali metal
For the following element, write its chemical symbol, determine the name of the group to which it belongs , and indicate whether it is a metal, metalloid, or nonmetal: (c) magnesium
Explain the difference between an element and a compound.
For the following element, write its chemical symbol, determine the name of the group to which it belongs , and indicate whether it is a metal, metalloid, or nonmetal: (d) argon
For the following element, write its chemical symbol, determine the name of the group to which it belongs , and indicate whether it is a metal, metalloid, or nonmetal: (e) sulfur
Classify each element as atomic or molecular. a) neonb) fluorinec) potassiumd) nitrogen
The elements of group 4A show an interesting change in properties moving down the group. Give the name and chemical symbol of each element in the group and label it as a nonmetal, metalloid, or metal.
Determine whether or not each element has molecules as its basic units. a) hydrogenb) iodinec) leadd) oxygen
Which elements do you expect to lose electrons in their chemical reactions? Which do you expect to gain electrons?i. Gaii. Pbiii. Cliv. N
Select all the diatomic elements.
Which of the following is an atomic element?A) BrB) HC) ND) OE) Mg
Which elements from this list are main group elements?a. telluriumb. potassiumc. vanadiumd. manganese
Which elements from this list are transition elements? a. Crb. Brc. Mod. Cs 
Classify each element as an alkali metal, alkaline earth metal, halogen, or noble gas.a. Fb. Src. Kd. Nee. At
What is the charge on the most stable ion of each of the following elements? K, I, Mg, O, Al, N, Ba, S
Which pair of elements do you expect to be most similar? Why? a. N and Nib. Mo and Sn c. Na and Mg d. Cl and F e. Si and P 
Using the periodic table, predict the charges of the ions of the following element: (a) Ga
Using the periodic table, predict the charges of the ions of the following element: (b) Sr
Using the periodic table, predict the charges of the ions of the following element: (c) As
Using the periodic table, predict the charges of the ions of the following element: (d) Br
Using the periodic table, predict the charges of the ions of the following element: (e) Se
Using the periodic table to guide you, predict the chemical formula and name of the compound formed by the following elements: (a) Ga and F
Using the periodic table to guide you, predict the chemical formula and name of the compound formed by the following elements: (b) Li and H
Using the periodic table to guide you, predict the chemical formula and name of the compound formed by the following elements: (c) Al and I
Using the periodic table to guide you, predict the chemical formula and name of the compound formed by the following elements: (d) K and S
The element fluorine is classified in the periodic table as a/an a. metal. b. alkali metal. c. metalloid. d. halogen.
The symbol for each of the following elements are: Calcium, Chromium, Carbon, Phosphorous, and Iodine a. C, Cr, Ca, Po, I b. Ca, Cr, C, P, I c. C, Cr, Ca, P, I d. Ca, Cr, C, Ph, I e. none of them
The periodic table is based on an element's a. molecular size. b. atomic mass. c. atomic number. d. molecular mass.
Dalton used the lightest element as his standard for atomic mass. What is this element? a. Oxygen b. Carbon c. Hydrogen d. Nitrogen
The two most reactive families of elements are the halogens and the alkali metals. How do they differ in their reactivities?
What is the name for each of the following groups in the periodic table? Group 1A                     Group 2A                     Group 6A                     Group 7A                     Group 8A
Distinguish between the following terms.a. molecule versus ion
Distinguish between the following terms.d. anion versus cation
Which of the following statements are true? For the false statements, correct them.b. Element 118 should be a nonmetal.
Which of the following statements are true? For the false statements, correct them.c. Hydrogen has mostly metallic properties.
Which of the following statements are true? For the false statements, correct them.d. A family of elements is also known as a period of elements.
Which of the following statements are true? For the false statements, correct them.e. When an alkaline earth metal, A, reacts with a halogen, X, the formula of the covalent compound formed should be A2X.
Which of the following elements is a halogen? A) Ne             B) I                     C) O             D) K                 E) Mg
What are the symbols of the following metals: sodium, radium, iron, gold, manganese, lead?
What are the symbols of the following nonmetals: fluorine, chlorine, bromine, sulfur, oxygen, phosphorus?
Give the names of the metals that correspond to the following symbols: Sn, Pt, Hg, Mg, K, Ag.
Give the names of the nonmetals that correspond to the following symbols: As, I, Xe, He, C, Si.
a. Classify the following elements as metals or nonmetals:    Mg     Si      Rn    Ti       Ge     Eu    Au      B       Am    Bi       At      Br
Identify the elements that correspond to the following atomic numbers. Label each as either a noble gas, a halogen, an alkali metal, an alkaline earth metal, a transition metal, a lanthanide metal, or an actinide metal.b. 4
Identify the elements that correspond to the following atomic numbers. Label each as either a noble gas, a halogen, an alkali metal, an alkaline earth metal, a transition metal, a lanthanide metal, or an actinide metal.f. 92
What is the identity of element Q if the ion Q 2+ contains 10 electrons?       A) Ne              B) O                 C) Mg              D) C
Fill in the blanks to complete the sentences below.  1. Copper, silver, and gold have all been know since ancient times because they appear in nature in  ________   and were thus discovered thousands of years ago. But the majority of elements  ________   and consequently, are hard to found in nature. Readily oxidized so that they are covered with coloured film Upper ground and water Elemental form Every most known compounds are deep in ground readily form compounds
Classify each element as a metal, nonmetal, or semimetal.a. Asb. Brc. Pbd. Fee. Krf. Sn
Classify each element as a metal, nonmetal, or semimetal. a. S  b. At c. He d. Al e. Mn f. Sr  
The ion N3- has ___________ protons and _____________ electrons?Enter the chemical symbol of the element.
What is the chemical symbol for potassium?a. Pb. Poc. Pud. K 
Enter the symbols for the ions with the following numbers of protons and electrons.a. 30 protons and 28 electronsb. 9 protons and 10 electronsc. 82 protons and 78 electronsd. 34 protons and 36 electrons
State the number of electrons lost or gained when the following elements form ions: Sb, Group 2A, As, Te, I
Which of the following forms cations that can have different charges? a. lead b. cobalt c. Cr d. Ce e. all of the aboveWhich among the following elements does not exist as a diatomic molecule in nature? a. hydrogen b. nitrogen c. fluorine d. neon e. none of these What is the charge on the radium ion? a. 1+ b. 2+ c. 3+ d. 1- e. 2-What is the correct formula of a compound that contains three sulfide ions and two aluminum ions? a. S3Al2 b. S2Al3 c. Al2S3 d. Al3S2 e. none of the above
Part AWhich row of the periodic table contains the most recently discovered elements? Express your answer as an integer. Part BCan you suggest a reason? 
Give the symbol for an element that is 1) a halogen. ____ 2) an alkali metal. ____ 3) a noble gas. ____ 4) an alkaline earth metal. ____
The element sulfur is in group ____ and period _____. The element gallium is in group ______ and period ______. The element nickel is in group _____ and period ______.
Which element does X represent in the following expression: 5525X? Enter the chemical symbol of the element.
Give the symbol for an element that is
Which of the following elements do NOT normally exist as diatomic molecules?
Elements in group 1A are best describe as:(i) Alkali Metals. Soft, silvery metals that react rapidly with water.(ii) Halogens. Colorful, corrosive nonmetals.(iii) Alkaline Earth Metals. Silvery meatls that are less reactive that alkali metals.(iv) Noble Gases. Colorless gases with very low chemical reactivity.
Which of these is least characteristic of metals?a. Moderately high melting pointb. Brittlenessc. Malleabilityd. Good thermal conductivitye. Good electrical conductivity 
What is the name of the alkali metal that is in period 2? What is the name of the halogen that is in period 5? What is the name of the alkaline earth metal that is in period 3? What is the name of the noble gas that is in period 3?
Match the following symbols with their elements names.
Which of the following elements consists of molecules containing four atoms? Choose the correct answer below. a. fluorine b. sulfur c. phosphorus d. bromine e. none of these is correct