Chapter 13: The Periodic Table Flashcards
What is the periodic table?
A table of elements arranged in order of increasing proton number (atomic number) to show the similarities of the chemical elements with related electronic configurations.
What are groups?
Vertical columns of the Periodic Table containing elements with similar chemical properties; the atoms of elements in the same group have the same number of electrons in their outer energy levels.
What are periods?
A horizontal row of the Periodic Table
What are metalloids? (2)
-An element that shows some of the properties of the metals and some of the non-metals.
eg boron and silicon
-They are close to the line that separates metals and nonmetals.
Properties of metalloids? (2)
-They often look like metals but are brittle like non-metals.
-They are neither conductors nor insulators but make excellent semiconductors.
What are the main group elements? (2)
-The elements in the other groups of the periodic table, excluding the transition elements.
-These vertical groups show most clearly how elements within the same group have similar chemical and physical properties.
What are transitional elements? (3)
Between the main group elements (G2 and G3) lies a block of metals known as transitional elements.
-They form the central region of the periodic table.
-They are hard, strong, dense metals which form compounds that are often coloured.
What are alkali metals?
Elements in Group 1 of the Periodic Table; They are the most active group of metals.
Why is hydrogen not placed in a group in the periodic table? (2)
-It is the smallest atom of all it’s properties are distinctive ad unique.
-It does not fit well in the trends of any group.
Properties of hydrogen
-Gas at room temperature.
-Non-metal, forms diatomic molecules.
-Atom has one electron in its outer shell.
-Atom can form either a positive or a negative ion: can gain one electron or lose its only electron.
What is a periodic properly?
A property of the elements that shows a repeating pattern when plotted against proton number (z).
Properties of groups (2)
-Elements in the same group have the same number of electrons in their outer shell.
-For main group elements, the number of the group is the number of electrons in the outer shell.
Properties of the periodic table?
Periodic Number shows how many shells of the electrons the atom has.
What does the outer electrons of an atom show?
It is mainly responsible for the chemical properties of any element and therefore elements in the same group will have similar.
What are noble gases?
They have the most stable arrangements and therefore they are unreactive. They are elements in Group VIII- a group of stable very unreactive gases.