Term | Definition |
period | horizontal row of elements in the periodic table whose properties change gradually and predictably |
group | family of elements in the periodic table that have similar physical or chemical properties |
representative elements | elements in Groups 1 & 2, and 13 - 18 in the periodic table that include metals, metalloids and nonmetals |
transition elements | elements in Groups 3 - 12 in the periodic table, all of which are metals |
metal | element that has luster,
is malleable and ductile,
is a good conductor of heat and electricity |
metalloid | element that shares some properties with metals and nonmetals |
nonmetals | element that is usually a gas or brittle solid at room temperature and is a poor conductor of heat and electricity |
How did Mendeleev arrange the periodic table? | by increasing atomic mass |
How did Moseley arrange the periodic table? | by increasing atomic number |
How is the modern periodic table arranged? | by increasing atomic number |
Where are metals located on the periodic table? | to the left of the stair step line |
Where are the nonmetals located on the periodic table? | to the right of the stair step line plus Hydrogen |
Where are the metalloids located on the periodic table? | along the stair step line except Aluminum which is a metal |
oxidation number | the number of electrons an atom will gain, lose or share in order to bond and complete its outer energy level. A '+' means the atom will LOSE electrons. A '-' means the atom will GAIN electrons. |
valence electrons | electrons in the outer most energy level |
ionic bond | bond between metals and nonmetals |
covalent bond | bond between nonmetals or 2 atoms of the same element |
metallic bond | bond between metals |
What is the maximum number of valence electrons? | 8 |
Where do you look on the periodic table to quickly tell the number of energy levels an element has? | the period number |
Where do you look on the periodic table to quickly tell the number of valence electrons an element has? | at the one's place of the group number -
Group 1 has 1 valence electron -
Group 17 has 7 valence electrons |
Octet Rule | atoms gain, lose or share electrons until they have a full outer shell (most need 8 valance electrons to be stable)
Hydrogen and Helium are exceptions |
'+' oxidation number | a '+' means an atom will lose electrons |
'-' oxidation munber | a '-' means an atom will gain electrons |
properties of metals | shiny, ductile, malleable,conductor of heat & electricity |
properties of nonmetals | dull, brittle, insulator |
properties of metalloids | properties of both metals & nonmetals |
When you are making a compound, the oxidation numbers should add up to what number? | 0 |
synthetic | elements made in a lab |