![]() For example: Li, Na, and K are much more reactive than are Ca, Sr, and Ba Li, Na, and K form compounds with oxygen in a ratio of two of their atoms to one oxygen atom, whereas Ca, Sr, and Ba form compounds with one of their atoms to one oxygen atom. However, the specific properties of these two groupings are notably different from each other. ![]() A second grouping includes calcium (Ca), strontium (Sr), and barium (Ba), which also are shiny, good conductors of heat and electricity, and have chemical properties in common. One such grouping includes lithium (Li), sodium (Na), and potassium (K): These elements all are shiny, conduct heat and electricity well, and have similar chemical properties. Identify metals, nonmetals, and metalloids by their properties and/or location on the periodic tableĪs early chemists worked to purify ores and discovered more elements, they realized that various elements could be grouped together by their similar chemical behaviors.Predict the general properties of elements based on their location within the periodic table.State the periodic law and explain the organization of elements in the periodic table.It is important to recognize which numbering system is being used and to be able to find the number of valence electrons in the main block elements regardless of which numbering system is being used. You will come across periodic tables with both numbering systems. In this numbering system, group 1A is group 1 group 2A is group 2 the halogens (7A) are group 17 and the noble gases (8A) are group 18. The elements in this group are also gases at room temperature.Īn alternate numbering system numbers all of the \(s\), \(p\), and \(d\) block elements from 1-18. ![]() We will learn the reason for this later, when we discuss how compounds form. These elements also have similar properties to each other, the most significant property being that they are extremely unreactive, rarely forming compounds. This group contains very reactive nonmetal elements. Group 7A (or 17) elements are also called halogens. It is important to recognize a couple of other important groups on the periodic table by their group name. Remember, Mendeleev arranged the table so that elements with the most similar properties were in the same group on the periodic table. The same pattern is true of other groups on the periodic table. Once again, because of their similarities in electron configurations, these elements have similar properties to each other. Group 2A is also called the alkaline earth metals. Although most metals tend to be very hard, these metals are actually soft and can be easily cut. Group 1A is also known as the alkali metals. Because of their similarities in their chemical properties, Mendeleev put these elements into the same group. ![]() The elements in 1A are all very reactive and form compounds in the same ratios with similar properties with other elements. This is what causes these elements to react in the same ways as the other members of the family. All of the 1A elements have one valence electron. A group is a vertical column of the periodic table. Remember that Mendeleev arranged the periodic table so that elements with the most similar properties were placed in the same group.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |