Bell Work • Name three common traits for each of the following: Alkali Metals, Alkaline Earth Metals, Lanthanides, and Actinides.
Bell Work
• Name three common traits for each of the following: Alkali Metals, Alkaline Earth Metals, Lanthanides, and Actinides.
Physical Science – Lecture 60
Non-Metals and Metalloids
Metalloids
• Elements that have some properties of metals and some properties of nonmetals are called metalloids.
What are the Properties of the Metalloids?
• The boiling points, melting points, and densities of the metalloids vary.
• The metalloids make good semiconductors.
Where are the Metalloids?
• The metalloids are located along the diagonal line between the metals and nonmetals in the periodic table.
Nonmetals
• Elements that don't have the properties of metals are called nonmetals.
Where are the Non-metals?
• The nonmetals are located on the upper right side of the periodic table, separated from metals by a line that cuts diagonally through the periodic table.
Who’s in the Family?
• The nonmetal element group is usually considered to consist of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, and selenium.
• It also includes halogens and noble gases.
Common Traits of Nonmetals
• The nonmetals are poor conductors of heat and electricity.
• Solid nonmetals are brittle and lack metallic luster.
• Most nonmetals gain electrons easily.
Common Traits of Non-Metals
• Nonmetals have high ionization energies and electronegativities.
THE NOBLE or INERT GASES
• These gases are located in the far right column of the periodic table.
• This is group 8A, 18 or 0 depending on the textbook.
WHO'S IN THE FAMILY?
• Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).
Noble Gases
• All of the inert gases have full outer shells with 8 electrons (except Helium who only has 2).
• This makes them non-reactive.
Common Traits of Noble Gases
• The noble gases have low boiling points and are all gases at room temperature.
Their Usefulness
• Neon is used in advertising signs. • Argon is used in light bulbs. • Helium is used to cool things and in balloons. • Xenon is used in headlights for new cars.
Summary of Common Properties
• Fairly nonreactive • Complete valence shell • High ionization energies • Very low electronegativities • Low boiling points (all gases at room
temperature)
HALOGENS
• Halogens (halogen family) are in Group 17 or 7A.
Who is in this family?
• The elements included are Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At).
Shared Traits
• They all have seven electrons in their outer shell.
• They need one electron to have a full shell.•
Common Traits
• Halogens range from solid (I2) to liquid (Br2) to gaseous (F2 and Cl2) at room temperature.
• The halogens have very high electronegativities.
• These nonmetals form ions with a -1 charge.
Reactivity
• Fluorine is actually the most reactive element of all. It is a halogen.
• As you move down the group, reactivity decreases for the halogens.
HALIDES
• When a halogen combines with another element, the resulting compound is called a halide.
Their Usefulness
• You find these elements in bleaches, disinfectants, and salts.
Summary of Common Properties
• Very high electronegativities • Seven valence electrons (one short of a stable
octet) • Highly reactive, especially with alkali metals
and alkaline earths
Groups 13-15: Not all one Type
• Groups 13-15 include some metals, some metalloids, and some nonmetals.
• The transition from metal to nonmetal is gradual across the periodic table.
Common Trends in Mixed Groups
• Remember that even in mixed groups of elements, the trends in the periodic table still hold true.
• Atom size, ease of removing electrons, and ability to form bonds can be predicted as you move across and down the table.