1. Kinds of Substances
Unit 4

2. Elements and Their Properties
Chapter 12

3. 12:1 Metals LT: -To understand metals and their properties. SC: I can…
Describe the properties of a typical metal.
Identify the alkali and alkaline earth metals.
Differentiate among 3 groups of transition elements.

4. 12:1 Metals Properties of Metals:
What do gold, copper, tin, iron, and aluminum have in common with one another?
Metals:
Mostly hard and solid at room temperature.
Good conductors (heat and electricity)
Shiny
Malleable: They can be hammered into sheets.
Ductile: They can be drawn into wires.

5. Atoms tend to have 1-3 valence electrons in their outer shells.
They tend to lose these to other atoms easily.
We already talked about ionic and covalent bonding.
In a 3rd type of bond, a metallic bond, metallic ions (positively charged) are surrounded by outer level electrons that are not held to one particular nucleus.

6. Metallic bonding explains many properties of metals:
Metal can be hammered or “stretched” without breaking because the ions are layered and can slide past one another.
Since electrons move fairly freely, they can carry energy through metal objects.
This allows for metal to be a good conductor of energy.

7. Why are these only found in compounds in nature?
The Alkali Metals:
The elements in Group 1 of the Periodic Table are called the alkali metals.
Why are these only found in compounds in nature?
These are highly reactive!
This is because all of these only have one electron in their outer shell, which they will readily give up.
Alkali metals tend to be part of many salts needed for living things.
Francium is extremely rare and radioactive.
The nucleus of a radioactive element breaks down and gives off particles and energy.

8. The Alkaline Earth Metals:
Group 2 of the periodic table is comprised of the alkaline earth metals.
These are also pretty reactive and are only found in nature in compounds.
Atoms of alkaline earth metals have 2 valence electrons, which they readily give up when bonding.
Many of these metals are common in living things and everyday objects.
Magnesium can be seen in some flash bulbs, baseball bats, chlorophyll.
Calcium is a main ingredient in bones
Barium is used to diagnose disorders.

9. Transition elements belong to groups 3-12 in the periodic table.
These are less reactive metals.
We will look at a couple groups.

10. These are the first elements in groups 8-10.
Iron, Cobalt, Nickel:
These are the first elements in groups 8-10.
They form the Iron Triad. What are they used for?
They are the only elements that create a magnetic field.
These metals are quite abundant and used in many things, especially iron.

11. Copper, Silver, and Gold: What are their uses?
The 3 metals of group 11., also known as the “coinage metals.”
Due to their lack of reactivity, they can be found as elements in nature.
Uses: wiring (copper), jewelry (all 3), photographic film (silver), coins (all 3), etc.

12. Zinc, Cadmium, and Mercury: What do these get used for?
These elements make up group 12.
Zinc is used as a coat/plate for other metals, but also oxidizes in nature.
Cadmium is used for plating and in rechargeable batteries. (Toxic)
Mercury is liquid at room temperature.
Used in thermometers, thermostats, batteries, etc.
Highly poisonous and builds up in the body over time.

13. Learning Checkpoint:
You are given a piece of the element palladium. How would you test it to see if it is a metal?
On the periodic table, how does the arrangement of the iron triad differ from the arrangements of the coinage metals and of the zinc group?
If X stands for metal, how can you tell from the formulas XCl and XCl2 which compound contains an alkali metal and which contains an alkaline earth metal?

14. 12:2 Synthetic Elements Learning Targets:
To understand synthetic elements and their usefulness.
Success Criteria:
I can…
Distinguish among elements classified as lanthanides, actinides, and transuranium elements.
Compare the pros and cons of synthesizing elements.

15. 12:2 Synthetic Elements Why Make Elements?
If you look at periods 6-7 on the periodic table, you will see breaks in the atomic numbers.
These missing elements are found at the bottom.
Elements #57-70 are called the lanthanides.
Elements # are called actinides.

16. Any element with an atomic number greater than 92 (Uranium) is called a transuranium element.
These are unstable and radioactive.
In periods 6 & 7 (mostly in the lanthinides and actinides) and with one element in period 5, we have synthetic elements.
A synthetic element can only be made in the laboratory and is not found in nature, even in a compound.

17. If an element doesn’t actually exist outside of lab, why would we make it?
They can be useful to us!
Americium is used in many smoke alarms.
Europium and Ytterbium are used in tvs (they glow)
Plutonium provides nuclear energy and weaponry.
Downside… All synthetic elements are radioactive and can be very harmful!

18. Learning Checkpoint Compare the lanthinide and actinide series.
What are the transuranium elements?
One use for technetium is to prevent corrosion of iron. Why do you think technetium is not found in nature?

19. 12:3 Nonmetals Learning Target:
To understand examples, properties, and uses of nonmetals.
Success Criteria:
I can…
Recognize hydrogen as a nonmetal.
Compare and contrast properties of the halogen.
Describe properties and uses of the noble gases.

20. 12:3 Nonmetals Properties of Nonmetals:
Most nonmetals are gases at room temperature.
Several are solid and one is liquid.
Solids nonmetals are:
Dull
Brittle and powdery
Poor conductors of energy
Not malleable or ductile (What does this mean again?)

21. Nonmetals can be part of an ionic compound or a covalent compound.
Do you remember the ingredients for each?

22. Hydrogen is the most abundant element in the Universe (more than 90%)!
Pure hydrogen is unstable and is not found in nature.
Gaseous hydrogen is a diatomic molecule.
Diatomic molecules consist of 2 atoms of the same element.
Hydrogen usually gives up electrons, but can be an acceptor when reacting with an alkali or alkaline earth metal.
If controlled, hydrogen will be the greatest nonpolluting fuel we have.
It reacts with oxygen to produce water!

23. Halogens belong to family 17.
The Halogens:
Halogens belong to family 17.
They all have 7 electrons in their outer shell
When halogens react with metal, they form a salt.
Halogen means “salt former.”
Halogens, in gaseous state, form diatomic covalent molecules.
What does this mean again?

24. In what ways do we use halogens in our lives?
Halogen light bulbs
Fluoride is in toothpaste and water to protect teeth.
Chlorine is used as a disinfectant and bleaching agent.
Bromine is used as a dye in cosmetics.
It’s the only nonmetal that is liquid at room temperature.
Iodine is a disinfectant and is needed as a trace element in our diet to prevent goiter.

25. The Noble Gases:
The noble gases make up group 18.
They do not react naturally to form compounds.
Their outer energy level is full of electrons.
How do we use them?

26. Learning Checkpoint:
What are 2 ways in which hydrogen combines with other elements?
Compare bromine to other halogens.
What property of noble gases makes them useful?
Chlorine and oxygen can combine to form a compound that can kill harmful microscopic organisms in water. What type of bond would you predict for this compound?

27. 12:4 Mixed Groups Learning Targets:
To understand the groups composed of metalloids, nonmetals and/or metals.
Success Criteria:
I can…
Distinguish among metals, nonmetals, and metalloids in Groups in the Periodic Table.
Describe the nature of allotropes.
Recognize the significance of differences in crystal structure in carbon.

28. 12:4 Mixed Groups The Boron Group: This is group 13.
Composed of 1 metalloid and the rest are metals.
Uses:
Boron is common in borax and boric acid (antiseptic).
Aluminum is used in a lot of stuff.
Gallium, indium, and thallium are used to produce semiconductors.
These conduct electric currents under certain conditions.

29. Each member has 4 electrons in its outer energy level.
The Carbon Group:
This is group 14.
Each member has 4 electrons in its outer energy level.
Carbon is a nonmetal
Silicon and germanium are metalloids
Tin and lead are metals.

30. Carbon exists in many forms.
Allotropes are different forms of the same element having different molecular structures.
Graphite consists of hexagonal layers of carbon atoms.
The weak bonding between layers allows for easy sliding.
In diamond, the atoms are bonded to 4 others to form a tetrahedron.
These tetrahedrons join together to make a very strong, crystalline structure.
Uses?

31. Germanium is also a metalloid semiconductor. Tin and lead are metals.
Silicon
Consists of 2 allotropes and is similar to the structure of diamond.
This is a metalloid semiconductor.
Germanium is also a metalloid semiconductor.
Tin and lead are metals.
Tin is used to coat metals and protect them from corrosion.
Can be used to produce bronze and pewter
Lead is toxic and its use is limited in modern days.

32. Members of group 15 have 5 electrons in their outer shell.
The Nitrogen Group:
Members of group 15 have 5 electrons in their outer shell.
They tend to share electrons and form covalent compounds.
Nitrogen is necessary for life
Found in DNA, RNA, fertilizers, and is the most abundant gas in the atmosphere.
Phosphorus, a nonmetal, has 3 allotropes.
It is used in matches, fertilizers, and water softeners.
Arsenic is a toxic metalloid.
Antimony and bismuth are used with metals to lower their melting points.

33. The Oxygen Group:
Group 16 has 6 electrons in the outer energy level.
Oxygen is a nonmetal needed for many things, including respiration and ozone.
Sulfur is a nonmetal that exists in many forms. It is used in paints, gunpowder, and a few other things.
The other 3 elements are not used much.

34. Learning Checkpoint:
Why are groups 14 and 15 better representatives of mixed groups than groups 13 or 16?
Why is graphite a lubricant while diamond is the hardest gem known?
After being refined from ore, bismuth metal is often used in metal mixtures that need a low melting point, such as those used in fire sprinklers. Is bismuth more metallic or less metallic than nitrogen? In compounds, would bismuth be more likely to have a positive oxidation number or a negative oxidation number?