Wednesday, July 25, 2012

Groups of the Periodic Table

There is an amazing amount of order that is in the periodic table. The more you learn about chemistry the more amazing it seems that the elements have been arranged in such a way. There are many similar properties that are observed across certain elements, and some of the properties are very evident in the groups (columns) of the periodic table. Let's take a look.



Here you can see the numbered groups across the top, 1-18. Many of these groups contain elements that are oddly similar to each other in the way that they behave, react, look, or some other property.

Group 1 (excluding hydrogen) is the alkali earth metal group. Lithium (Li), sodium (Na), Potassium (K), Rubidium (Rb), and Cesium (Cs) are all pretty soft metals that have a silvery color about them. They all react quickly and often violently with water. They are never found in nature in their pure form as they quickly react with other things. Francium (Fr) is an alkali metal but it is so rare that not a whole lot is known about it.

The elements of Group 2 are known as alkaline earth metals. They are also silvery and react with water, but they are less reactive than the alkali metals. They are reactive enough, though, that they are also not found in nature in pure form.

Group 17 contains Halogens. Halogens are nonmetals and corrosive. They are found in nature combined with other elements in salts. The kind of salt you eat is sodium chloride (NaCl)

Group 18 consists of the noble gasses. Noble are colorless and very low in reactivity, so they keep to themselves.

All elements colored pink in this table are known as the transition metals. This is a very big group and contains many elements with varying properties.

On top of all this, all elements are categorized into 3 major types of elements: nonmetals, semi-metals, and metals.


Non metals are, in our table, the elements colored purple and green (don't forget about hydrogen!). Most of the nonmetals are gasses at room temperature, and the ones that are solid are opaque and usually brittle.


Semi metals are, in our table, the dark teal colors consisting of Silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te). Sometimes boron (B) and astatine (At) are included, making a zigzag between the nonmetals and metals. Semimetals' properties are intermediates of metals and nonmetals. They tend to be silvery and solid, but brittle and poor conductors.

Metals are all other elements: the pink, light blue, gold, and apricot colors. All excpet mercury (Hg) are solid at room temperature and usually have that shininess that we associate with metals we're familiar with in everyday life. Metals are great conductors of electricity and heat, and are malleable rather than brittle.

No comments:

Post a Comment