PERIODIC TABLE - INTRODUCTION #1

PERIODIC TABLE MODULES This set of modules are on the design & use of the Periodic  Table.  Proceed through each module's readings & watching the video clips for details.  Take notes as needed!!! COMPLETE the "ELEMENT of the DAY" COMPLETE the 5 (FIVE) SUPERHERO ELEMENTAL  TRADING CARDS.

INTRODUCTION TO PERIODIC TABLE CHART

The most important chemistry chart there is, and the cornerstone of science since 1869

• The Periodic Table is a chart which arranges the chemical elements in a useful, logical manner.   
• Elements are listed in order of increasing atomic number, lined up so that elements which exhibit similar properties are arranged in the same row or column as each other. 
• The Periodic Table is one of the most useful tools of chemistry and the other sciences. 

Here are 10 fun and interesting Periodic Table facts:

1. While Dmitri Mendeleev is most often cited as the inventor of the modern periodic table, his table was just the first to gain scientific credibility, and not the first table that organized the elements according to periodic properties.
2. There are 90 elements on the periodic table that occur in nature. All of the other elements are strictly man-made.
3. Technetium was the first element to be made artificially.
4. The International Union of Pure Applied Chemistry, IUPAC, revises the periodic table as new data becomes available. At the time of this writing, the most recent version of the periodic table was approved 19 February 2010.
5. The rows of the periodic table are called periods. An element's period number is the highest unexcited energy level for an electron of that element.
6. Columns of elements help to distinguish groups in the periodic table. Elements within a group share several common properties and often have the same outer electron arrangement.
7. Most of the elements on the periodic table are metals. The alkali metals, alkaline earths, basic metals, transition metals, lanthanides and actinides all are groups of metals.
8. The present periodic table has room for 118 elements. Elements aren't discovered or created in order of atomic number. Scientists are working on creating and verifying element 120, which will change the appearance of the table.
9. Although you might expect atoms of an element to get larger as their atomic number increases, this does not always occur because the size of an atom is determined by the diameter of its electron shell. In fact, element atoms usually decrease in size as you move from left to right across a row or period.
10. The main difference between the modern periodic table and Mendeleev's periodic table is that Mendeleev's table arranged the elements in order of increasing atomic weight while the modern table orders the elements by increasing atomic number.

We sometimes use the terms atom and element to mean the same thing.

As far as we know, there are only so many basic elements. Up to this point in time, we have discovered/created over 120. While there may be more out there to discover, the basic elements remain the same.

Iron (Fe) atoms found on Earth are identical to iron atoms found on meteorites. The iron atoms on Mars that make the soil red are the same too. 

With the tools you learn here, you can explore and understand the Universe. You will never stop discovering new reactions and compounds, but the elements will remain the same. 

The List of Elements

Let’s start with 18 ELEMENTS.   "Why start with 18?"  Because the rules for the first eighteen elements are very straightforward: 

1)       Electrons fit nicely into three shells.

·          Remember that the shells are the places you will find the electrons as they spin around the nucleus. 

2)           These elements make up most of the matter in the Universe.

3)           It's a lot easier to remember facts about 18 elements than over 100 elements.

Who are we kidding? We know you want information on more than eighteen elements. We've added the next 18 elements from the fourth period (row) of the periodic table. You need to remember that this is the first row with transition elements. The transition metals have electron configurations that are a little different from the first 18 elements. Make sure you understand the first 18 before you move on to this set. 

Elements as Building Blocks

As you probably saw, the periodic table is organized like a big grid. The elements are placed in specific locations because of the way they look and act. If you have ever looked at a grid, you know that there are rows (left to right) and columns (up and down). The periodic table has rows and columns, and they each mean something different. 

You've got Your Period/Rows...

REVIEW

Even though they skip some squares in between, all of the rows go left to right. When you look at a periodic table, each of the rows is considered to be a different period (Get it? Like PERIODic table.).

In the periodic table,

·          elements have something in common if they are in the same row.

·          All of the elements in a period have the same number of atomic orbitals.

Every element in the top row (the first period) has one orbital for its electrons.

All of the elements in the second row (the second period) have two orbitals for their electrons.

It goes down the periodic table like that. At this time, the maximum number of electron orbitals or electron shells for any element is seven. 

...and Your Groups

Now you know about periods. The periodic table also has a special name for its columns.

·        When a column goes from top to bottom, it's called a group.

·        The elements in a group have the same number of electrons in their outer orbital.

·        Those outer electrons are also called valence electrons. They are the ones involved in chemical bonds with other elements. 

Every element in the first column (group one) has one electron in its outer shell. Every element in the second column (group two) has two electrons in the outer shell. As you keep counting the columns, you'll know how many electrons are in the outer shell. There are some exceptions to the order when you look at the transition elements, but you get the general idea. Transition elements start to add electrons to the second-to-last shell. 

Two at the Top

Hydrogen (H) and helium (He) are special elements. 

Hydrogen can have the talents and electrons of two groups: one and seven. To scientists, hydrogen is sometimes missing an electron, and sometimes has an extra one. 

Helium is different from all of the other elements. It can only have two electrons in its outer shell. Even though it only has two, it is still grouped with elements that have eight (i.e., noble gases).

The noble gases and helium are all "happy," because their outermost electron shell is full. The elements in the center section are called transition elements. They have special electron rules too. 

·  

PERIODIC TABLE - GETTING TO KNOW THE ELEMENTS

HAPPY HALLOWEEN

CHEMISTRY - DANGER MODULE #11

Dangerous Particles

Radioactivity occurs when an atomic nucleus breaks down into smaller particles. There are three types of particles: alpha, beta, and gamma. Alpha particles are positively charged, beta particles are negatively charged, and gamma particles have no charge. The particles also have increasing levels of energy. Alpha has the lowest energy, beta has a bit more, and then gamma is the fastest and most energetic of all the emission particles. 

The term half-life describes the time it takes for the amount of radioactivity to go down by one-half. Let's say you have some uranium (U) (don't try this at home!) and it's radioactive. When your measurements tell you that the level of radioactivity has gone down by one-half, the amount of time that has passed is the half-life. Every isotope has its own unique half-life. The half-life of uranium-235 is 713,000,000 years. The half-life of uranium-238 is 4,500,000,000 years. That's a long time to wait for the radioactivity to decrease. 

Harnessing the Energy

Nuclear energy is the energy released when the nuclei (nuclei is the plural of nucleus) of atoms split or are fused. You know the nucleus is made up of protons and neutrons. Nuclear forces hold all of the pieces together. Fusion is when two nuclei come together. Fission is when one nucleus is split into two or more parts. Huge amounts of energy are released when either of these reactions occurs. Fusion reactions create much of the energy given off by the Sun. Fission creates the much smaller particles that make up the protons and neutrons that physicists are studying every day. In our nuclear reactors, fission is the main process. In the Sun, fusion is the big process. 

Atoms from the Mirror Universe

Since we're talking a little bit about atomic and nuclear physics, we wanted to tell you about antimatter. It's not just found in television shows. Scientists have proved that it is real. While a regular atom has positive and neutral pieces (protons/neutrons) in the nucleus and negative pieces in orbiting clouds (electrons), antimatter is just the opposite. Antimatter has a nucleus with a negative charge and little positive pieces in the orbits. Those positively charged pieces are called positrons. According to news reports in 2010, scientists at CERN (a particle collider) created antihydrogen atoms. They couldn't really do anything with them, since they lasted for less than a second... but they made them! 

CHEMISTRY - ELEMENT OF THE DAY - SULFUR

16

S

Sulfur

32.065

Atomic Number: 16

Atomic Weight: 32.065

Phase at Room Temperature: Solid

Element Classification: Non-metal

Period Number: 3    Group Number: 16   

Group Name: Chalcogen

What's in a name? From the Sanskrit word sulvere and the Latin word sulphurium.

Say what? Sulfur is pronounced as SUL-fer.

History and Uses:

Sulfur, the tenth most abundant element in the universe, has been known since ancient times. Sometime around 1777, Antoine Lavoisier convinced the rest of the scientific community that sulfur was an element. Sulfur is a component of many common minerals, such as galena (PbS), gypsum (CaSO₄·2(H₂O), pyrite (FeS₂), sphalerite (ZnS or FeS), cinnabar (HgS), stibnite (Sb₂S₃), epsomite (MgSO₄·7(H₂O)), celestite (SrSO₄) and barite (BaSO₄). Nearly 25% of the sulfur produced today is recovered from petroleum refining operations and as a byproduct of extracting other materials from sulfur containing ores. The majority of the sulfur produced today is obtained from underground deposits, usually found in conjunction with salt deposits, with a process known as the Frasch process.

Sulfur is a pale yellow, odorless and brittle material. It displays three allotropic forms: orthorhombic, monoclinic and amorphous. The orthorhombic form is the most stable form of sulfur. Monoclinic sulfur exists between the temperatures of 96°C and 119°C and reverts back to the orthorhombic form when cooled. Amorphous sulfur is formed when molten sulfur is quickly cooled. Amorphous sulfur is soft and elastic and eventually reverts back to the orthorhombic form.

Most of the sulfur that is produced is used in the manufacture of sulfuric acid (H₂SO₄). Large amounts of sulfuric acid, nearly 40 million tons, are used each year to make fertilizers, lead-acid batteries, and in many industrial processes. Smaller amounts of sulfur are used to vulcanize natural rubbers, as an insecticide (the Greek poet Homer mentioned "pest-averting sulphur" nearly 2,800 years ago!), in the manufacture of gunpowder and as a dying agent.

In addition to sulfuric acid, sulfur forms other interesting compounds. Hydrogen sulfide (H₂S) is a gas that smells like rotten eggs. Sulfur dioxide (SO₂), formed by burning sulfur in air, is used as a bleaching agent, solvent, disinfectant and as a refrigerant. When combined with water (H₂O), sulfur dioxide forms sulfurous acid (H₂SO₃), a weak acid that is a major component of acid rain.

SCIENCE NEWS - When to Catch a Lie via Text # 22

You’re texting with a friend. The back and forth is fast and furious. Until…there’s an awkwardly long pause. You might think, aw, they just got another call, or had to get back to their dinner, whatever. But maybe…they’re about to lie.
At least that was one conclusion from an experiment published in a journal called ACM Transactions on Management Information Systems.
Scientists had 100 participants converse via online text with a specially developed computer program. The computer asked each participant 30 questions. And the participants were instructed to lie in half the responses. The researchers found that the lies took 10 percent longer to write, were shorter and were edited more than the truthful messages. 
How can you tell if someone is heavily editing a text? Newer smartphones let you know when the other person is typing. A lot of starting and stopping could mean the texter is carefully constructing a response that might not hold up in a court of law.
Bottom line: dishonest texts take longer on average to write—but it’s also possible your friend may be making an honest attempt to fix those pesky incorrect auto-corrects.
—Christie Nicholson

CHEMISTRY - ELEMENT OF THE DAY - PHOSPHORUS

15

P

Phosphorus

30.973762

Atomic Number: 15

Atomic Weight: 30.973762

Phase at Room Temperature: Solid

Element Classification: Non-metal

Period Number: 3    Group Number: 15    

Group Name: Pnictogen

What's in a name? From the Greek word for light bearing, phosphoros.

Say what? Phosphorus is pronounced as FOS-fer-es.

History and Uses:

In what is perhaps the most disgusting method of discovering an element, phosphorus was first isolated in 1669 by Hennig Brand, a German physician and alchemist, by boiling, filtering and otherwise processing as many as 60 buckets of urine. Thankfully, phosphorus is now primarily obtained from phosphate rock (Ca₃(PO₄)₂).

Phosphorus has three main allotropes: white, red and black. White phosphorus is poisonous and can spontaneously ignite when it comes in contact with air. For this reason, white phosphorus must be stored under water and is usually used to produce phosphorus compounds. Red phosphorus is formed by heating white phosphorus to 250°C (482°F) or by exposing white phosphorus to sunlight. Red phosphorus is not poisonous and is not as dangerous as white phosphorus, although frictional heating is enough to change it back to white phosphorus. Red phosphorus is used in safety matches, fireworks, smoke bombs and pesticides. Black phosphorus is also formed by heating white phosphorus, but a mercury catalyst and a seed crystal of black phosphorus are required. Black phosphorus is the least reactive form of phosphorus and has no significant commercial uses.

Phosphoric acid (H₃PO₄) is used in soft drinks and to create many phosphate compounds, such as triple superphosphate fertilizer (Ca(H₂PO₄)₂·H₂O). Trisodium phosphate (Na₃PO₄) is used as a cleaning agent and as a water softener. Calcium phosphate (Ca₃(PO₄)₂) is used to make china and in the production of baking powder. Some phosphorus compounds glow in the dark or emit light in response to absorbing radiation and are used in fluorescent light bulbs and television sets.

SCIENCE NEWS - Protect Infants from Whooping Cough by Vaccinating Older Kids # 21

Whooping cough, also called pertussis, can cause fatal respiratory failure in infants. Now a study finds that one way to help protect the very young from this disease is vaccination—of kids a few years older than the babies.  
The recent resurgence of pertussis led to a 2006 recommendation by the Centers for Disease Control and Prevention that adolescents be vaccinated. The current study used pre-2006 data to estimate the number of babies who would have been hospitalized for pertussis had the vaccination effort not occurred.
Researchers found that the actual number of infants hospitalized in the years since the adolescent immunization program started was far lower than what would have been forecast.
For example, in 2011 adolescent vaccination led to a greater than 70 percent reduction in infant hospital cases. Credit goes to so-called herd immunity: protected people means more dead ends for an infection trying to spread. The work is in the journal Pediatrics. [Katherine A. Auger, Stephen W. Patrick and Matthew M. Davis, Infant Hospitalizations for Pertussis Before and After Tdap Recommendations for Adolescents]
Sadly, a thousand babies still got sick. Vaccinations for people of all ages will help smother pertussis in the crib.
—Sophie Bushwick

CHEMISTRY - ELEMENT OF THE DAY - ALUMINUM

13

Al

Aluminum

26.9815386

Atomic Number: 13

Atomic Weight: 26.9815386

Phase at Room Temperature: Solid

Element Classification: Metal

Period Number: 3    Group Number: 13    

Group Name: none

What's in a name? From the Latin word for alum, alumen.

Say what? Aluminum is pronounced as ah-LOO-men-em.

History and Uses:

Although aluminum is the most abundant metal in the earth's crust, it is never found free in nature. All of the earth's aluminum has combined with other elements to form compounds. Two of the most common compounds are alum, such as potassium aluminum sulfate (KAl(SO₄)₂·12H₂O), and aluminum oxide (Al₂O₃). About 8.2% of the earth's crust is composed of aluminum.

Scientists suspected than an unknown metal existed in alum as early as 1787, but they did not have a way to extract it until 1825. Hans Christian Oersted, a Danish chemist, was the first to produce tiny amounts of aluminum. Two years later, Friedrich Wöhler, a German chemist, developed a different way to obtain aluminum. By 1845, he was able to produce samples large enough to determine some of aluminum's basic properties. Wöhler's method was improved in 1854 by Henri Étienne Sainte-Claire Deville, a French chemist. Deville's process allowed for the commercial production of aluminum. As a result, the price of aluminum dropped from around $1200 per kilogram in 1852 to around $40 per kilogram in 1859. Unfortunately, aluminum remained too expensive to be widely used.

Two important developments in the 1880s greatly increased the availability of aluminum. The first was the invention of a new process for obtaining aluminum from aluminum oxide. Charles Martin Hall, an American chemist, and Paul L. T. Héroult, a French chemist, each invented this process independently in 1886. The second was the invention of a new process that could cheaply obtain aluminum oxide from bauxite. Bauxite is an ore that contains a large amount of aluminum hydroxide (Al₂O₃·3H₂O), along with other compounds. Karl Joseph Bayer, an Austrian chemist, developed this process in 1888. The Hall-Héroult and Bayer processes are still used today to produce nearly all of the world's aluminum.

With an easy way to extract aluminum from aluminum oxide and an easy way to extract large amounts of aluminum oxide from bauxite, the era of inexpensive aluminum had begun. In 1888, Hall formed the Pittsburgh Reduction Company, which is now known as the Aluminum Company of America, or Alcoa. When it opened, his company could produce about 25 kilograms of aluminum a day. By 1909, his company was producing about 41,000 kilograms of aluminum a day. As a result of this huge increase of supply, the price of aluminum fell rapidly to about $0.60 per kilogram.

Today, aluminum and aluminum alloys are used in a wide variety of products: cans, foils and kitchen utensils, as well as parts of airplanes, rockets and other items that require a strong, light material. Although it doesn't conduct electricity as well as copper, it is used in electrical transmission lines because of its light weight. It can be deposited on the surface of glass to make mirrors, where a thin layer of aluminum oxide quickly forms that acts as a protective coating. Aluminum oxide is also used to make synthetic rubies and sapphires for lasers.

CHEMISTRY - BONDS MODULE #8

BONDING

Bonding Basics

You must first learn why atoms bond together. We use a concept called "Happy Atoms." We figure that most atoms want to be happy, just like you. 

The idea behind Happy Atoms is that atomic shells like to be full. That's it. If you are an atom and you have a shell, you want your shell to be full. Some atoms have too many electrons (one or two extra). These atoms like to give up their electrons. Some atoms are really close to having a full shell. Those atoms go around looking for other atoms who want to give up an electron. 

Let's take a look at some examples. 

We should start with the atoms that have atomic numbers between 1 and 18. 

There is a 2-8-8 rule for these elements. 

• The first shell is filled with 2 electrons
• the second is filled with 8 electrons
• third is filled with 8. 

You can see that sodium (Na) and magnesium (Mg) have a couple of extra electrons. They, like all atoms, want to be happy. They have two possibilities: they can try to get to eight electrons to fill up their third shell, or they can give up a few electrons and have a filled second shell.

•  It is always easier to give away one or two electrons than it is to go out and find six or seven to fill your shells. 

What a coincidence! Many other atoms are interested in gaining a few extra electrons. 

Oxygen (O) and fluorine (F) are two good examples. Each of those elements is looking for a couple of electrons to make a filled shell. They each have one filled shell with two electrons, but their second shells want to have eight. There are a couple of ways they can get the electrons. 

• They can share electrons, making a covalent bond, or they can just borrow them, and make an ionic bond (also called electrovalent bond). 

So, let’s say we've got a sodium atom that has an extra electron. We've also got a fluorine atom that is looking for one. 

When they work together, they can both wind up happy! Sodium gives up its extra electron. The sodium then has a full second shell and the fluorine (F) also has a full second shell. Two happy atoms! When an atom gives up an electron, it becomes positive like the sodium ion (Na⁺). When an atom gets an extra electron, it becomes negatively charged like the fluorine ion (F^-). 
The positive and negative charges continue to attract each other like magnets. The attraction of opposite charges is the way they form and maintain the bond. 

• Any atoms in an ionic/electrovalent bond can get or give up electrons.