1. Chemical Families Chemistry 5(B)
Knowing the properties of each chemical family on the periodic table will help you utilize the periodic table.
Chemical Families
Chemistry 5(B)

2. Chemical Families Lesson Objectives
Identify and explain the properties of chemical families in the periodic table
Alkali metals
Alkaline earth metals
Transition metals
Halogens
Noble gases
This presentation will teach you how to identify and explain the properties of chemical families in the periodic table, including the alkali metals, alkaline earth metals, transition metals, halogens, and the noble gases.

3. The Periodic Table
Periodic table – table that displays the elements in order of increasing atomic number and organizes them according to chemical properties
Elements arranged in a periodic pattern
Behavioral trends of an element can then be predicted by knowing its position on the table
The periodic table displays the elements in order of increasing atomic number and organizes them according to chemical properties. Since elements are arranged in a “periodic” pattern, behavioral trends of an element can then be predicted by knowing its position on the table.

4. The Periodic Table
The periodic table pictured can be broken down into sections and studied in more detail. By learning the organization of the periodic table and why it is arranged in this manner, we can learn more about elements’ physical attributes as well as their behavioral patterns based on their location on the table.

5. Periods and Groups Periodic table is arranged in
Periods – rows on the periodic table
Groups – columns on the periodic table
Also called families, since elements in groups share similar chemical properties
The periodic table is arranged into seven periods or rows, as well as 18 groups or columns. Groups are also called families, since elements in groups share similar chemical properties.

6. Numbering Groups Groups are numbered 1–18 or 1–8 with A/B notation
Tall columns are notated as “A”
Main group elements
Short columns are notated as “B”
1A 2A
3A 4A 5A 6A 7A 8A
3B 4B 5B 6B 7B B B 2B
Groups are numbered either one through eighteen or one through eight with an “A” notation given to the tall columns and “B” notation to the short columns. Group A elements are known as the main group elements. Main group elements tend to show periodic patterns most clearly and consistently.
Main Group Elements

7. Chemical Families Family names Group 1A –– alkali metals
Group 2A –– alkaline earth metals
Group 7A –– halogens
Group 8A –– noble gas
Group 1–8B –– transition metals
1A 2A
3A 4A 5A 6A 7A 8A
3B 4B 5B 6B 7B B B 2B
Family names may also be used instead of group numbers. Group 1A elements are known as the alkali metals; group 2A elements are the alkaline earth metals; group 7A elements are the halogens and the group 8A elements are the noble gases. The short groups in the middle of the table, groups 1–8B, are collectively called the transition metals.

8. Decoding the Periodic Table
Arrangement of elements on periodic table help predict physical and chemical properties including
Physical state
Boiling, melting, or freezing point
Density
Metallic and nonmetallic character
Reactivity
Likelihood of gaining or losing electrons
Valence – number of electrons in the atom’s valence or outermost energy level
The arrangement of elements on the periodic table can help us predict their physical and chemical properties. Trends in physical and chemical properties shown by the periodic table include trends in the physical state of the element, its boiling, melting, or freezing point, its density, its metallic or nonmetallic character, its reactivity, its likelihood of gaining or losing electrons, and its valence. Valence is the number of electrons in the atom’s valence or outermost energy level.

9. Metals, Nonmetals, and Metalloids
Step-wise line that begins at the element boron and moves downward in a zigzag pattern divides the table
Metals are to the left of the line
Nonmetals are to the right of the line
Along the line are the metalloids
Possess properties of both metals and nonmetals
Metalloids
The periodic table may be divided into a left half and right half using a step-wise line that begins at the element boron and moves downward in a zigzag pattern. To the left of the line are the metals and to right are nonmetals. Along the line are the semi-metals or metalloids, shown in blue in the image, which possess properties of both metals and nonmetals.

10. Metallic and Nonmetallic Character
Metals tend to lose electrons to form cations
Cations – positively charged particles
Other properties of metals
Lustrous, good conductors, malleable, and ductile
Nonmetals gain electrons to form anions
Anions – negatively charged particles
Other properties of nonmetals
Many are gases at room temperature, solids are usually brittle, and are typically poor conductors
We can derive general information about an element simply by looking to the table to see if it is a metal or nonmetal.
Metals tend to lose electrons to form cations or positively charged particles. Metals are lustrous, good conductors of electricity, malleable, and ductile.
Nonmetals, on the other hand, gain electrons to form anions or negatively charged particles. Many nonmetals are gases at room temperature, brittle as solids, and are typically poor conductors.

11. Chemical Properties
Elements in the same group will have similar chemical properties
Group number of group A elements equals the number of valence electrons
Valence electrons – electrons in the valence or outermost energy level, which are most likely to be lost, gained, or shared
Determines the oxidation number of an element
Positive if electrons are lost
Positive charge equals the number of electrons lost
Negative if electrons are gained
Negative charge is equal in magnitude to the number of electrons gained
Chemical properties tell us about how elements in a group react, or how they will behave with other elements. Elements in the same group, or family, will have similar chemical properties. The group number of group A elements can tell us many things, such as the number of valence electrons, which are the electrons in the valence or outermost energy level. They are the electrons that are most likely to be lost, gained, or shared.
The group number of group A elements also determines the oxidation number, or charge of an element as an ion. The oxidation number is positive if electrons are lost. The positive charge is equal to the number of electrons lost. The oxidation number is negative if electrons are gained. The magnitude of the charge is equal to the number of electrons gained.

12. Chemical Properties
Reactivity is determined by the ability to gain, lose, or share electrons in order to achieve an octet
Octet – eight electrons in the valence energy level
Noble gases naturally have an octet
Extremely low reactivity
Other groups attempt to achieve octets by gaining, losing, or sharing electrons
Higher reactivity
Types of elements involved in the reaction will determine how the octet is achieved
Metals tend to lose electrons when reacting with nonmetals
Nonmetals tend to gain electrons when reacting with metals and share electrons when reacting with other nonmetals
Reactivity is also determined by the ability to gain, lose, or share electrons in order to achieve an octet. An octet is achieved when there are eight electrons in the valence energy level. Noble gases naturally have an octet and therefore, have extremely low reactivity. Other groups attempt to achieve octets by gaining, losing, or sharing electrons. This means that they have higher reactivity than the noble gases.
The types of elements involved in the reaction will determine how the octet is achieved. When reacting with nonmetals, metals tend to lose electrons to attain octet. On the other hand, nonmetals tend to gain electrons when reacting with metals and share electrons when reacting with other nonmetals.

13. By Felix Burton (Flickr) [CC-BY-2.0]
Noble Gases
Noble gases
Gases at room temperature
Relatively inert
Have full valence shells
Typically don’t form ions 8A 18
By Felix Burton (Flickr) [CC-BY-2.0]
The first group we will discuss is Group 8A, the noble gases. These elements are gases at room temperature. They are relatively inert or nonreactive because they already have full valence shells. Therefore, noble gases don’t typically lose or gain electrons to form ions. The noble gases include helium, neon, argon, krypton, xenon, and radon. Noble gases such as neon gas are commonly used in so called “neon signs.”

14. Halogens Halogens Highly reactive nonmetals
Seven valence electrons
One electron away from having an octet
Gain one electron to achieve octet
Ions have -1 charge
Very electronegative
Electronegative – possessing the ability to acquire electrons readily
Form ionic bonds by accepting electrons from metals
Form covalent bonds by sharing electrons with other nonmetals
Combine with H+ to form acids 7A 17
Group 7A, the halogens, are highly reactive nonmetals containing seven valence electrons. In other words, they are one electron shy of an octet. They gain an electron to complete their octet and have a -1 charge as ions as a result. Because they are very close to achieving an octet, they are very electronegative or possess the ability to acquire electrons readily. Halogens form ionic bonds by accepting electrons from metals and covalent bonds by sharing electrons with other nonmetals. Halogen ions also combine with hydrogen ions to form acids in solutions. The halogens include fluorine, chlorine, bromine, iodine, and astatine.

15. Alkaline Earth Metals Alkaline earth metals Highly reactive metals
Two valence electrons
Two electrons away from having an octet
Loses two electrons to attain octet
Ions have +2 charge
Form oxides by combining with oxygen
Form ionic bonds with nonmetals, creating salts
Combine with OH– to form bases 2A 2
Group 2A, the alkaline earth metals, are also highly reactive. They contain two valence electrons and are two electrons away from having an octet. They lose their two valence electrons to attain their octet, giving their ions a +2 charge. Alkaline earth metals form oxides by combining with oxygen. They can also form ionic bonds with nonmetals to create salts. Ions of alkaline earth metals combine with hydroxide ions to form bases in solutions. The alkaline earth metals include beryllium, magnesium, calcium, strontium, barium, and radium.

16. Alkali Metals Alkali Metals Highly reactive metals
One valence electron
One electron away from having an octet
Lose one electron to attain an octet
Ions have +1 charge
Form oxides by combining with oxygen
Form ionic bonds with nonmetals, creating salts
Combine with OH– to form strong bases 1A 1
Group 1A, the alkali meals, are highly reactive metals with one valence electron. They are one electron away from forming an octet. They readily lose one electron in order to attain an octet and form ions with +1 charge as a result. Just like the alkaline earth metals, alkali metals form oxides by combining with oxygen and create salts by forming ionic bonds with nonmetals. Ions of alkali metals also combine with hydroxide ions to form strong bases in solutions. The alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium.

17. Transition Metals
Groups 1–8B are collectively called the transition metals
Transition in oxidation numbers
Form different compounds with nonmetals as a result of variance in charges
Less reactive than alkali metals or alkaline earth metals
3B 4B 5B 6B 7B B B 2B
The 10 short columns in the middle of the periodic table, groups I-VIIIB are collectively called the transition metals. They vary or transition in oxidation number even within the same group. Therefore, transition metals can form different compounds with nonmetals as a result of the variance in charges. For example, iron can have a oxidation number of either +2 or +3. Therefore, iron can form either iron(III) oxide, which has the formula Fe2O3, or iron(II) oxide, which has the formula FeO, when combined with oxygen. While they are still reactive, transition metals are less reactive than alkali metals or alkaline earth metals. Examples of transition metals include familiar metals such as iron, gold, copper, nickel, and silver.

18. Chemical Families Lesson Objectives
Identify and explain the properties of chemical families in the periodic table
Alkali metals
Alkaline earth metals
Transition metals
Halogens
Noble gases
This concludes our presentation on the chemical families. You now know how to identify and explain the properties of chemical families in the periodic table, including the alkali metals, alkaline earth metals, transition metals, halogens, and the noble gases.