1. Elements and their Properties
Chapter 17
Elements and their Properties

2. Properties of Metals
In the periodic table, metals are elements found to the left of the stair-step line.

3. Properties of Metals Metals good conductors of heat and electricity
all but one are solid at room temperature.
reflect light~luster. Typically shiny
malleable -hammered or rolled into sheets.
ductile -drawn into wires

4. Ionic Bonding in Metals
one to three electrons in their outer energy levels.
chemical reactions
metals tend to give up electrons easily because of the strength of charge of the protons in the nucleus.

5. Ionic Bonding in Metals
metals combine with nonmetals,
the atoms of the metals tend to lose electrons to the atoms of nonmetals, forming ionic bonds.
Both become more chemically stable when they form ions.

6. Metallic Bonding In metallic bonding
positively charged metallic ions are surrounded by a cloud of electrons
Outer-level electrons are NOT held tightly to the nucleus of an atom.
the electrons move freely among many positively charged ions.

7. Metallic Bonding metallic bonding metal
explains many of the properties of metals.
metal
When hammered into sheets or drawn into a wire, it does not break because the ions are in layers that slide past one another without losing their attraction to the electron cloud.
good conductors of electricity because the outer-level electrons are weakly held.

8. The Alkali Metals Group 1 of the periodic table
one electron in its outer energy level (most reactive of all the metals)
don’t occur in nature in their elemental form and are stored in substances that are unreactive, such as an oil.

9. The Alkaline Earth Metals
two electrons in its outer energy level (still highly reactive)
These electrons are given up when an alkaline earth metal combines with a nonmetal

10. Transition Elements
Transition elements are those elements in Groups 3 through 12 in the periodic table.
Transition elements are familiar because they often occur in nature as uncombined elements

11. The Inner Transition Metals
The two rows of elements that seem to be disconnected from the rest on the periodic table are called the inner transition elements

12. The Inner Transition Metals
They are called this because like the transition elements, they fit in the periodic table between Groups 3 and 4 in periods 6 and 7, as shown.

13. The Lanthanides
The first row includes a series of elements with of 58 to 71.
These elements are called the lanthanide series because they follow the element lanthanum.

14. The Actinides
The second row of inner transition metals includes elements with atomic numbers ranging from 90 to 103.
These elements are called the actinide series because they follow the element actinium.
All of the actinides are radioactive and unstable.
Thorium and uranium are the actinides found in the Earth’s crust in usable quantities.

15. Properties of Nonmetals
Periodic table
all nonmetals except hydrogen are found at the right of the stair-step line.

16. Properties of Nonmetals
your body’s mass is made of oxygen, carbon, hydrogen, and nitrogen
calcium, a metal, and other elements make up the remaining four percent of your body’s mass

17. Properties of Nonmetals
elements that usually are gases or brittle solids at room temperature
don’t conduct heat or electricity well, and generally they are not shiny.
as a group, nonmetals are poor conductors of heat and electricity.
form both ionic and covalent compounds.
gain electrons from metals, the nonmetals become negative ions in ionic compounds.
atoms of nonmetals usually share electrons to form covalent compounds.

18. Hydrogen Hydrogen atoms in the universe, Water
about 90 percent of them are hydrogen.
found mostly in the compound water
Water
when broken down into its elements, hydrogen becomes a gas made up of diatomic molecules.

19. Hydrogen Diatomic molecule
two atoms of the same element in a covalent bond

20. Hydrogen Hydrogen highly reactive.
a single electron, which the atom shares when it combines with other nonmetals.
can gain an electron when it combines with alkali and alkaline earth metals.
forms hydrides.

21. The Halogens Halogen lights
contain small amounts of bromine or iodine.
These elements, as well as fluorine, chlorine, and astatine, are called halogens and are in Group 17.

22. The Halogens Halogens very reactive in their elemental form
their compounds have many uses.

23. The Halogens Halogen seven electrons in its outer energy level
only one electron is needed to complete this energy level.
if a halogen gains an electron from a metal, an ionic compound, called a salt is formed.

24. The Halogens Gaseous state form reactive diatomic covalent molecules
can be identified by their distinctive colors.
chlorine is greenish yellow, bromine is reddish orange, and iodine is violet.

25. The Noble Gases The noble gases exist as isolated atoms
stable~ their outermost energy levels are full.
no naturally occurring noble gas compounds are known

26. The Noble Gases Noble gases Helium Neon and argon
stability what makes them useful
Helium
light weight makes it useful in lighter-than-air blimps and balloons
Neon and argon
used in “neon lights” for advertising.

27. Properties of Metalloids
share unusual characteristics
form ionic and covalent bonds with other elements
have metallic and nonmetallic properties

28. Properties of Metalloids
some can conduct electricity better than most nonmetals
not as well as some metals, giving them the name semiconductor.
except for aluminum the metalloids are the elements in the periodic table that are located along the stair-step line

29. The Boron Group Boron, metalloid, first element in Group 13
borax laundry products to soften water.
boric acid, a mild antiseptic.

30. The Carbon Group
Group 14
carbon family, has four electrons in its outer energy level
where much of the similarity ends.

31. The Carbon Group Carbon Silicon and germanium Tin and lead nonmetal
metalloid
Tin and lead
metals.

32. Allotropes of Carbon Diamond, graphite, and buckminsterfullerene
are allotropes of an element.
Allotropes
forms of the same element that have different molecular structures.

33. Allotropes of Carbon Diamond,
each carbon atom is bonded to four other carbon atoms at the vertices, or corner points, of a tetrahedron
many tetrahedrons join together to form a giant molecule in which the atoms are held tightly in a strong crystalline structure.

34. Allotropes of Carbon Buckminsterfullerene discovered in the mid-1980s
soccer-ball-shaped molecule, informally called a buckyball
named after the architect-engineer R. Buckminster Fuller
designed structures with similar shapes.

35. Allotropes of Carbon Graphite Diamonds
allotrope of carbon that is soft and can be used as a lubricant
Diamonds
allotrope of carbon that is hard and is often used in jewelry.

36. The Nitrogen Group Nitrogen family Group 15.
five electrons in its outer energy level
tend to share electrons
form covalent compounds with other elements.

37. The Nitrogen Group Nitrogen fourth most abundant element in your body.
each breath is about 80 percent gaseous nitrogen in the form of diatomic molecules, N2.

38. Uses of the Nitrogen Group
Phosphorus
nonmetal that has three allotropes.
Antimony
metalloid
Bismuth
metal
both elements are used with other metals to lower their melting points.

39. The Oxygen Group Group 16 Oxygen oxygen group.
nonmetal, exists in the air as diatomic molecules, O2.
during electrical storms, some oxygen molecules, O2, change into ozone molecules, O3.

40. The Oxygen Group sulfur Sulfur second element in the oxygen group
nonmetal that exists in several allotropic forms.
exists as different-shaped crystals and as a noncrystalline solid.

41. The Oxygen Group Tellurium and polonium Selenium metalloids nonmetal
one of several that you need in trace amounts in your diet.
toxic if too much of it gets into your system.
most common of these three.

42. Synthetic Elements Synthetics
smashing existing elements with particles accelerated in a heavy ion accelerator, scientists have been successful in creating elements not typically found on Earth.
more than 92 protons
except for technetium-43 and promethium-61

43. Synthetic Elements Plutonium can be changed to americium, element 95.
used in home smoke detectors.

44. Transuranium Elements
elements having more than 92 protons, the atomic number of uranium
do not belong exclusively to the metal, nonmetal, or metalloid group.

45. Transuranium Elements
synthetic and unstable, and many of them disintegrate quickly.

46. Why make elements? Synthesized elements
by studying how they form and disintegrate, you can gain an understanding of the forces holding the nucleus together.
Radioactive elements can be useful.
technetium’s radioactivity makes it ideal for many medical applications.