What groups are there in the periodic table

We can sort the elements into large classes with common properties: metals elements that are shiny, malleable, good conductors of heat and electricity—shaded yellow ; nonmetals elements that appear dull, poor conductors of heat and electricity—shaded green ; and metalloids elements that conduct heat and electricity moderately well, and possess some properties of metals and some properties of nonmetals—shaded purple.

The elements can also be classified into the main-group elements or representative elements in the columns labeled 1, 2, and 13—18; the transition metals in the columns labeled 3—12; and inner transition metals in the two rows at the bottom of the table the top-row elements are called lanthanides and the bottom-row elements are actinides ; Figure 3.

The elements can be subdivided further by more specific properties, such as the composition of the compounds they form. For example, the elements in group 1 the first column form compounds that consist of one atom of the element and one atom of hydrogen. These elements except hydrogen are known as alkali metals , and they all have similar chemical properties. The elements in group 2 the second column form compounds consisting of one atom of the element and two atoms of hydrogen: These are called alkaline earth metals , with similar properties among members of that group.

Other groups with specific names are the pnictogens group 15 , chalcogens group 16 , halogens group 17 , and the noble gases group 18, also known as inert gases. The groups can also be referred to by the first element of the group: For example, the chalcogens can be called the oxygen group or oxygen family.

Hydrogen is a unique, nonmetallic element with properties similar to both group 1A and group 7A elements. For that reason, hydrogen may be shown at the top of both groups, or by itself. Figure 3. The periodic table organizes elements with similar properties into groups. Atoms of each of the following elements are essential for life. Give the group name for the following elements:. In studying the periodic table, you might have noticed something about the atomic masses of some of the elements.

The table has seven rows and 18 columns. Each row represents one period; the period number of an element indicates how many of its energy levels house electrons. Sodium, for instance, sits in the third period, which means a sodium atom typically has electrons in the first three energy levels. Moving down the table, periods are longer because it takes more electrons to fill the larger and more complex outer levels.

The columns of the table represent groups, or families, of elements. The elements in a group often look and behave similarly, because they have the same number of electrons in their outermost shell — the face they show to the world.

Group 18 elements, on the far right side of the table, for example, have completely full outer shells and rarely participate in chemical reactions. Elements are typically classified as either a metal or nonmetal, but the dividing line between the two is fuzzy. Metal elements are usually good conductors of electricity and heat. The subgroups within the metals are based on the similar characteristics and chemical properties of these collections. Our description of the periodic table uses commonly accepted groupings of elements, according to the Los Alamos National Laboratory.

Alkali metals: The alkali metals make up most of Group 1, the table's first column. Shiny and soft enough to cut with a knife, these metals start with lithium Li and end with francium Fr. So 2p2. So how many valence electrons does it have?

Well, in its second shell, its outermost shell, it has two plus two, it has four valence electrons, and that's going to be true for the things in this group, and because of that, carbon has similar bonding behavior to silicon, to the other things in its group. And we can keep going on, you know, for example, oxygen, oxygen and sulfur, these would both want to take two electrons from someone else because they have six valence electrons, they want to get to eight, so they have similar bonding behavior.

You go to this yellow group right over here, these are the halogens. So there's a special name for them. These are the halogens. And these are highly reactive, because they have seven valence electrons. They would love nothing more than to get one more valence electron, so they love to react, in fact, they especially love to react with the alkali metals over here.

And then finally, you get to kind of your atomic nirvana in the noble gases here. And so the noble gases, that's the other name for the group 18 elements, noble gases. And they all have the very similar property of not being reactive. Why don't they react? They have filled their outermost shell.

They don't find the need, they're noble, they're kind of above the fray, they don't find the need to have to react with anyone else. There are two different numbering systems that are commonly used to designate groups and you should be familiar with both. The traditional system used in the United States involves the use of the letters A and B. The first two groups are 1A and 2A, while the last six groups are 3A through 8A. The middle groups use B in their titles.

Unfortunately, there was a slightly different system in place in Europe. To eliminate confusion the International Union of Pure and Applied Chemistry IUPAC decided that the official system for numbering groups would be a simple 1 through 18 from left to right. Many periodic tables show both systems simultaneously. Skip to main content.

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