1. Chapter 3: Elements and the Periodic Table
Section 4: Nonmetals and Metalloids

2. Nonmetal An element that lacks most of the properties of a metal.
Most are poor conductors of electricity and heat and are reactive with other elements. Solid nonmetals are dull and brittle.

3. Physical Properties State
10 of 16 are gases at room temperature (O, N)
Others are solids (C, I, S)
1 is liquid (Br)
Solid nonmetals are generally opposite of metals
Dull (not shiny)
Brittle (not malleable or ductile): break or crumble if hit with hammer
Lower densities
Poor conductors of heat and electricity

4. Chemical Properties Reactivity
Most are reactive; readily form compounds
Fluorine (F) is the most reactive known element
Some, group 18, hardly ever form compounds
Electrons during reactions with other atoms
When nonmetals and metals react, electrons move from the metal to the nonmetal (NaCl)
When nonmetals form compounds with other nonmetals, they share electrons and become bonded together into molecules (CH4)

5. Checkpoint 1
What happens to the electrons in the atoms of nonmetals when they form bonds with other atoms?

6. Checkpoint 1
What happens to the electrons in the atoms of nonmetals when they form bonds with other atoms?
They either gain or share electrons.

7. Families of Nonmetals The Carbon Family The Nitrogen Family
The Oxygen Family
The Halogen Family
The Noble Gases
Hydrogen

8. The Carbon Family Group 14
Atoms can gain, lose, or share four electrons when reacting with other elements
Only carbon is a nonmetal
Carbon has an important role in the chemistry of life and fossil fuels

9. The Nitrogen Family Group 15 Two nonmetals: nitrogen and phosphorus
Usually gain or share three electrons when reacting with other elements
Nitrogen
Makes up 80% of atmosphere
Diatomic molecule: consists of two atoms
Nitrogen fixation by bacteria that turn it into useful form for plants
Phosphorus
Much more reactive, always found in compounds in nature
Used to make matches

10. The Oxygen Family Group 16
Contains three nonmetals: oxygen, sulfur, and selenium
Usually gain or share two electrons when reacting with other elements
Oxygen
Important to life
Diatomic (oxygen you breathe) O2
Sometimes triatomic (ozone) O3
Can combine with almost every other element (very reactive)
Most abundant in Earth’s crust, second-most abundant in atmosphere
Sulfur
Smells like rotten eggs
Used to make rubber, sulfuric acid

11. Checkpoint 2
Which family of elements gains or shares three electrons?

12. Checkpoint 2 Which family of elements gains or shares three electrons?
The Nitrogen family.

13. The Halogen Family Group 17 Fluorine (F), Chlorine (Cl)
Halogen: salt forming
All but astatine (At) are nonmetals
Typically gain or share one electron when they react with other elements
Very reactive; dangerous in uncombined form
Fluorine (F) is most reactive, reacts with almost every known substance
Useful in compounds
Ex. Fluorine compounds added to water supply to help prevent tooth decay

14. The Noble Gases
Group 18
Do not ordinarily form compounds because atoms of noble gases do not usually gain, lose, or share electrons (unreactive)
Found in small amounts in Earth’s atmosphere
Not discovered until the late 1800s

15. Hydrogen
Simplest and smallest atom: one proton and one electron (some isotopes of hydrogen also have neutrons)
Very different from other elements; not in a family  (hydrogen is not an alkali metal, even though it’s in the same column)
Makes up more than 90% of the atoms in the universe, but only 1% of the mass of Earth’s crust, oceans, and atmosphere
Rarely found as a pure element; usually in water molecules

16. The Metalloids Have some characteristics of both metals and nonmetals
All are solid at room temperature
Brittle, hard, and somewhat reactive
Most useful property is their varying ability to conduct electricity
Conductivity depends on temperature, exposure to light, or the presence of small amounts of impurities
Used to make semiconductors (substances that can conduct electricity under some conditions but not under other conditions) in computer chips, transistors, and lasers.
Most common is silicon (Si), which forms a compound with oxygen to make sand and glass

17. Checkpoint 3
Which family of nonmetals is unreactive?

18. Checkpoint 3
Which family of nonmetals is unreactive?
The noble gases.

19. Post-lesson Quiz Which is not a property of nonmetals? a. shininess
b. dullness
c. brittleness
d. poor conductivity

20. Post-lesson Quiz
2. Where are nonmetals generally located on the periodic table? a. on the right side b. in the middle c. on the left side d. interspersed throughout

21. Post-lesson Quiz
3. Some metalloids can conduct electricity under some conditions, but not others. Because of this, these metalloids are sometimes called… a. pseudo-conductors b. semiconductors c. hemiconductors d. biconductors

22. Post-lesson Quiz
4. Which element is the simplest and is not part of a family? a. helium b. lithium c. boron d. hydrogen

23. Post-lesson Quiz
5. What happens when nonmetal atoms form bonds with other atoms? a. they lose electrons b. they always gain electrons c. they sometimes gain and sometimes share electrons d. they always share electrons