Презентация Introduction to Periodic Table онлайн

Содержание слайда: Introduction to Periodic Table

Содержание слайда: Reading the Periodic Table

Содержание слайда: What is the Periodic Table? It is an organizational system for elements.

Содержание слайда: Who created it? The quest for a systematic arrangement of the elements started with the discovery of individual elements. By 1860 about 60 elements were known and a method was needed for organization.  In 1869, Russian chemist Dimitri Mendeleev proposed arranging elements by atomic weights and properties. The table contained gaps but Mendeleev predicted the discovery of new elements.

Содержание слайда: Periods = Rows 一排 The horizontal rows of the periodic table are called periods. Elements in a period are not similar in properties. All of the elements in a period have the same number of atomic orbitals 軌道. 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.

Содержание слайда: Periods = Rows Atomic mass increases from left to right across a period. Metals are on the left. Non-metals are on the right. The first element in a period is usually an active metal, and the last element in a period is always an inactive gas.

Содержание слайда: Groups = Columns縱列 The vertical columns of the periodic table are called groups. Elements in the same group have similar characteristics or properties. The elements in a group have the same number of electrons in their outer orbital. Those outer electrons are also called valence electrons 價電子. Every element in the first column (group 1) has one electron in its outer shell. Every element on the second column (group 2) has two electrons in the outer shell. As you keep counting the columns, you'll know how many electrons are in the outer shell. Atomic mass increases from top to bottom across a group.

Содержание слайда: What do all the numbers mean?

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Содержание слайда: Other than periods and groups, the table is divided into families

Содержание слайда: Hydrogen Hydrogen belongs to a family of its own. Hydrogen is a diatomic (H2), reactive gas. Hydrogen was involved in the explosion of the Hindenberg. Hydrogen is promising as an alternative fuel source for automobiles.

Содержание слайда: Alkali metals

Содержание слайда: Alkaline earth metals Second column on the periodic table (Group 2). They are very reactive metals, which are always combined with nonmetals in nature. Alkaline earths have low electronegativities. The alkaline earths have two electrons in the outer shell. The two valence electrons are not tightly bound to the nucleus, so the alkaline earths readily lose the electrons to form divalent cations. Several of these elements are important mineral nutrients, such as Mg and Ca.

Содержание слайда: Transition metals The transition elements are located in groups IB to VIIIB of the periodic table. These elements are very hard, with high melting points and boiling points. Moving from left to right across the periodic table, the five d orbitals become more filled. The d electrons are loosely bound, which contributes to the high electrical conductivity of the transition elements. They exhibit a wide range of positively charged forms. Allow them to form many different ionic and partially ionic compounds.

Содержание слайда: Rare earth elements The rare earth metals are found in group 3 of the periodic table, and the 6th (5d electronic configuration) and 7th (5f electronic configuration) periods. There are two blocks of rare earths, the lanthanide series and the actinide series. The rare earths are silver, silvery-white, or gray metals. The metals have high electrical conductivity. Many are man-made.

Содержание слайда: Other than periods and groups, the table is divided into families

Содержание слайда: Other metals They are usually in form of solid and have a high density.

Содержание слайда: Metalloids準金屬

Содержание слайда: Non-Metals

Содержание слайда: Halogens

Содержание слайда: Noble Gases

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Содержание слайда: Fun time~