CHEMISTRY - PERIODIC TABLE - TRANSITION METALS #8

Transitioning

Let's start off by telling you that there are a lot of elements that are considered transition metals. Which metals are the transition metals? 
21 (Scandium) through 29 (Copper)
39 (Yttrium) through 47 (Silver)
57 (Lanthanum) through 79 (Gold)
89 (Actinium) and all higher numbers.

What Makes Them So Special?

It all has to do with their shells/orbitals. We like introducing students to the first eighteen elements, because they are easier to explain. Transition metals are good examples of advanced shell and orbital ideas. They have a lot of electrons and distribute them in different ways. You will usually find that transition metals are shiny, too. Not all of them, but we are sure you've seen pictures of silver (Ag), gold (Au), and platinum (Pt). 

Transition metals are able to put more than eight electrons in the shell that is one in from the outermost shell. Think about argon (Ar). It has 18 electrons set up in a 2-8-8 order. Scandium (Sc) is only 3 spots away with 21 electrons, but it has a configuration of 2-8-9-2. Wow! This is where it starts. This is the point in the periodic table where you can place more than 8 electrons in a shell. You need to remember that those electrons are added to the second-to-last shells. 

The transition metals are able to put up to 32 electrons in their second-to-last shell. Something like gold (Au), with an atomic number of 79, has an organization of 2-8-18-32-18-1. Of course, there are still some rules. No shell can have more than 32 electrons. You will find it's usually 2, 8, 18 or 32 for the maximum number of electrons in an orbital. 

One More Thing

Most elements can only use electrons from their outer orbital to bond with other elements. Transition metals can use the two outermost shells/orbitals to bond with other elements. It's achemical trait that allows them to bond with many elements in a variety of shapes. Why can they do that? As you learn more, you will discover that most transition elements actually have two shells that are not happy. Whenever you have a shell that is not happy, the electrons want to bond with other elements. Example: Molybdenum (Mo), with 42 electrons. The configuration is 2-8-18-13-1. The shells with 13 and 1 are not happy. Those two orbitals can use the electrons to bond with other atoms. 

ELEMENT - PRACTICE GAME

ELEMENT JEOPARDY GAME


 My Jeopardy Template

CHEMISTRY - ELEMENT OF THE DAY - BORON

5

B

Boron

10.811

Atomic Number: 5

Atomic Weight: 10.811

Phase at Room Temperature: Solid

Element Classification: Semi-metal

Period Number: 2    Group Number: 13    

Group Name: none

What's in a name? From the Arabic word Buraq and the Persian word Burah, which are both words for the material "borax."

Say what? Boron is pronounced as BO-ron.

History and Uses:

Boron was discovered by Joseph-Louis Gay-Lussac and Louis-Jaques Thénard, French chemists, and independently by Sir Humphry Davy, an English chemist, in 1808. They all isolated boron by combining boric acid (H₃BO₃) with potassium. Today, boron is obtained by heating borax (Na₂B₄O₇·10H₂O) with carbon, although other methods are used if high-purity boron is required.

Boron is used in pyrotechnics and flares to produce a green color. Boron has also been used in some rockets as an ignition source. Boron-10, one of the naturally occurring isotopes of boron, is a good absorber of neutrons and is used in the control rods of nuclear reactors, as a radiation shield and as a neutron detector. Boron filaments are used in the aerospace industry because of their high-strength and lightweight.

Boron forms several commercially important compounds. The most important boron compound is sodium borate pentahydrate (Na₂B₄O₇·5H₂O). Large amounts of this compound are used in the manufacture of fiberglass insulation and sodium perborate bleach. The second most important compound is boric acid (H₃BO₃), which is used to manufacture textile fiberglass and is used in cellulose insulation as a flame retardant. Sodium borate decahydrate (Na₂B₄O₇·10H₂O), better known as borax, is the third most important boron compound. Borax is used in laundry products and as a mild antiseptic. Borax is also a key ingredient in a substance known as Oobleck, a strange material 6th grade students experiment with while participating in Jefferson Lab's BEAMS program. Other boron compounds are used to make borosilicate glasses, enamels for covering steel and as a potential medicine for treating arthritis.

CHEMISTRY - PERIODIC TABLE - ALKALINE EARTH METALS #7

ALKALINE METALS

Heading to Group Two

So we just covered the alkali metals in Group I. You will find the alkaline earth metals right next door in Group II. This is the second most reactivefamily of elements in the periodic table. 
Do you know why they are called alkaline? When these compounds are mixed in solutions, they are likely to form solutions with a pH greater than 7. Those higher pH levels means that they are defined as "basic" or "alkaline" solutions. 

A Family Portrait

Who's in the family? 
The members of the alkaline earth metals include: 

• beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra). 

As with all families, these elements share traits. While not as reactive as the alkali metals, this family knows how to make bonds very easily. Each of them has two electrons in their outer shell. They are ready to give up those two electrons in electrovalent/ionic bonds. Sometimes you will see them with two halogen atoms, as with beryllium fluoride (BeF₂), and sometimes they might form a double bond, as with calcium oxide (CaO). It's all about giving up those electrons to have a full outer shell. 

As you get to the bottom of the list, you will find the radioactive radium. While radium is not found around your house anymore, it used to be an ingredient in glow-in-the-dark paints. It was originally mixed with zinc sulfide (ZnS). The other elements are found in many items, including fireworks, batteries, flashbulbs, and special alloys. The lighter alkaline earth metals, such as magnesium and calcium, are very important in animal and plant physiology. You all know that calcium helps build your bones. Magnesium can be found in chlorophyll molecules. 

PUZZLEPRACTICE