Notes – Organization of the Periodic Table Chapter 7, Lesson 1

Mendeleev Russian scientist who published the first periodic table in 1869. He recognized that some elements have similar chemical and physical properties. Fluorine and chlorine are both gases that burn your lungs. Silver and copper are both shiny metals that tarnish when exposed to air.

Arrangement of Elements The periodic table contains information about the structures and characteristics of the elements. Elements are arranged in the periodic table in order of their atomic number. “Periodic” means regular, repeating pattern, and properties of elements repeat in each period (row).

Arrangement of Elements

Arrangement of Elements

Periods Elements are organized into horizontal periods and vertical groups.

Periods A horizontal row of elements in the periodic table is called a period. The atomic numbers increase by one from left to right across a period.

Groups A vertical column of elements in the periodic table is called a group. Groups are numbered 1–18 across the top of the periodic table. Elements in the same group have similar properties.

The Lanthanide and Actinide Series The two rows of elements at the bottom of the table are the Lanthanide Series and the Actinide Series (also called “rare earth metals”).

Metals Elements that are on the left side and in the middle of the periodic table are metals.

Metals Metallic refers to the properties of common metals. Luster, or shine, is one property of metals. Metals are also ductile and malleable. Conductivity is the ability of a material to transfer electricity or thermal energy, and metals are good conductors. luster ductile malleable conductivity

Metals Most metals are solids at room temperature because of their high melting point, with the exception of Mercury (Hg), a liquid at room temperature.

Metals

Nonmetals Elements on the right side of the periodic table are nonmetals.

Nonmetals Nonmetals exhibit properties that are the opposite of metals. They are poor conductors of heat and electricity, are brittle, and do not have luster. Nonmetals make up most of the matter in the living world.

Nonmetals Most are gases at room temperature. The solids, carbon (C) and iodine (I) are dull and brittle. Bromine (Br) is the only nonmetal that is liquid at room temperature. iodine carbon bromine

Nonmetals Group 17 elements are the halogens, which are the most reactive nonmetals, and most are dangerous to humans. Group 18 elements are the noble gases, which are extremely stable by themselves and occur in nature as single atoms, NOT compounds.

Semimetals 8 elements are semimetals, or metalloids.

Semimetals Semimetals have the properties of both metals and nonmetals. Semimetals conduct electricity but not as well as metals, so they are called semiconductors.

Other Periodic Tables A variety of periodic tables are designed to provide the information needed by different groups of people.

Arrangement of Elements

If a substance transfers electricity easily, it is said to be ____. 7.1 Organization of the Periodic Table If a substance transfers electricity easily, it is said to be ____. A malleable B conductive C metalloid D ductile

The most reactive nonmetals are the ____ in Group 17. A noble gases B halogens C semimetals D Actinide series

Fluorine has properties most similar to ____. A oxygen B neon 7.1 Organization of the Periodic Table Fluorine has properties most similar to ____. A oxygen B neon C lithium D chlorine

Which is a property of metals? A poor conductors B brittle C low melting point D luster

Which of the following is a noble gas? A nitrogen B oxygen C argon D bromine

Elements in a period are arranged ____. A by increasing atomic number right to left B by increasing atomic number left to right C by increasing valence electrons right to left D by increasing electric charge right to left

Which element is a gas at room temperature? A neon B bromine C magnesium D uranium

Nonmetals are located where on the periodic table? A top B bottom C right side D left side