The Periodic Table of Elements Station 1

The Periodic Table is a chart that arranges the elements according to their periodic or repeating patterns. In 1869, a Russian scientist named Dmitri Mendeleev noticed that when he arranged the elements into rows and columns by their increasing atomic mass, the elements with similar properties appeared next to each other. The Periodic Table that is used today is slightly different than Mendeleev’s original work. Today the elements are arranged by their atomic numbers instead of their mass numbers. The table is a useful tool for learning about the elements.

Groups Station 2

An element’s location on the table can help us predict the properties and behavior of the element. Elements with the most similar properties and behaviors are located in vertical columns. Vertical means up and down. These vertical columns are called groups. There are 18 groups on the Periodic Table numbered from left to right. Some of the groups have names such as the Noble Gases, the Halogens, and the Alkali Metals.

Noble Gases Station 3

The elements located in the far right column of Group 18 make up the Noble Gases. Helium, neon, argon, krypton, xenon, and radon are found in nature as gases that tend not to combine with other elements. Noble gases do not associate with “common” elements. To understand why, study the data in the table. Notice that for each element listed, the outermost energy level is holding the maximum number of electrons possible. For example, helium has one energy level, which can hold only two electrons. An atom of helium has 2 electrons in the outermost energy has two level is full. An atom of neon has 8 valence electrons which means its outermost energy level is full. The same is true of other Noble Gases. Therefore, Noble Gases are said to be stable or inert.

Elements that are not Noble Gases do not have atoms with filled outer energy levels. When outer energy levels are not complete, atoms tend to lose, gain, or share valence electrons with other atoms. Elements with completely full energy levels are extremely stable and tend to react with almost nothing else.

Alkali Metals Station 4

Elements with only one electron in the outermost energy level of their atoms are called the Alkali Metals. Since they have one valence electron, they are located in Group 1 of the Periodic Table. Alkali metals do not have complete outer energy outer energy levels. Therefore, they are not stable or inert. In fact, they tend to lose their one valence electron very easily so they can achieve a stable arrangement of electrons.


Halogens Station 5

Elements that have seven valence electrons in their atoms are called halogens. Since their outermost energy level is not filled, they are not stable or inert. Halogens need one additional electron to have a filled outer energy level. Therefore, atoms of halogens tend to gain one electron from other atoms so they can achieve a more stable arrangement of electrons.


Ions Station 6

When an atom loses or gains an electron it becomes either a positive or negative ion. An ion is an atom that has an electrical charge because it no longer has an equal number of protons and electrons. By gaining an electron, an atom increases its number of negative charges and becomes a negative ion. By losing an electron, an atom decreases its number of negative charges and becomes a positive ion.


Metals Station 6

Metals If you look at the periodic table, you will notice it is color coded. The colors represent elements that are metals, nonmetals, or metalloids. Examples of a metal, a nonmental, and a metalloid are illustrated in Figure 3. With the exception of mercury, all the metals are solids, most with high melting points. A metal is an element that has luster, is a good conductor of heat and electricity, is malleable, and is ductile. The ability to reflect light is a property of metals called luster. Many metals can be pressed or pounded into thin sheets or shaped into objects because they are malleable (MAL ee yuh bul). Metals are also ductile (DUK tul), which means that they can be drawn out into wires. Can you think of any items that are made of metals?

Non-Metals Station 7

Nonmetals are usually gases or brittle solids at room temperature and poor conductors of heat and electricity. There are only 17 nonmetals, but they include many elements that are essential for life: carbon, sulfur, nitrogen, oxygen, phosphorus, and iodine.

Element / Common Uses/Interesting Facts
Oxygen / Oxygen is essential to life. It is in the air we breathe and the water we drink.
Sulfur / Sulfur is distinctive because in its elemental form it is yellow. When burnt, it smells like rotten eggs.
Carbon / Elemental carbon is found as graphite (your pencil ‘lead’), coal, and diamonds.
Nitrogen / Nitrogen is essential to life. It is found in fertilizers for plants. Nitrogen is also a component of explosives.
Phosphorus / Phosphorus is essential to life. Phosphorus has been used in detergents. One form of phosphorus is very flammable.
Iodine / Iodine is an essential nutrient. It is often added to table salt to make sure that people get enough iodine in their diet. Check your salt at home to see if it is “iodized”.



Metalloids Station 8

The elements between metals and nonmetals on the periodic table are called metalloids. As you might expect from the name, a metalloid is an element that shares some properties with metals and some with nonmetals. These elements also are called semimetals.

Element / Common Uses/Interesting Facts
Boron / Extracted from an ore called “borax”, it is used in detergents and fire retardants.
Silicon / Used as a semiconductor in computer chips. It has given its name to an area in California known for its computer and electronics industry: Silicon Valley.
Germanium / Used in semiconductors and for infrared devices.
Tellurium / Tellurium is slightly toxic. It is used in electronics and catalysts.
Arsenic / Arsenic is very toxic. It is used as an insecticide as a wood preservative.