Parts of the Periodic Table
Elements are arranged in order by the number of their protons (atomic number).
Periods:
- Each row of the periodic table is a different period.
- Periods are numbered 1 through 7.
- Each element in a period has the same number of energy levels (elements in period 1 have 1 energy level, elements in period 2 have 2 energy levels, etc.).
Groups:
- Each column of the periodic table is a different group.
- Groups are numbered 1 through 18 (this is the modern way of numbering groups, many Periodic Tables still use an older method of roman numerals and letters to label the groups).
- Each element in a group (not including transition metals) will have the same number of valence electrons.
- Group 1 elements have 1 valence electron
- Group 2 elements have 2 valence electrons
- Group 13 elements have 3 valence electrons
- Group 14 elements have 4 valence electrons
- Group 15 elements have 5 valence electrons
- Group 16 elements have 6 valence electrons
- Group 17 elements have 7 valence electrons
- Group 18 elements have 8 valence electrons
Metals:
Physical Properties of Metals:
- Luster (shininess)
- Good conductors of heat and electricity
- High density (heavy for their size)
- High melting point
- Ductile (most metals can be drawn out into thin wires)
- Malleable (most metals can be hammered into thin sheets)
Chemical Properties of Metals:
- Easily lose electrons
- Corrode easily. Corrosion is a gradual wearing away. (Example: silver tarnishing and iron rusting)
Non-metals:
Physical Properties of Nonmetals:
- No luster (dull appearance)
- Poor conductor of heat and electricity
- Brittle (breaks easily)
- Not ductile
- Not malleable
- Low density
- Low melting point
Chemical Properties of Nonmetals:
- Tend to gain electrons
Since metals tend to lose electrons and nonmetals tend to gain electrons, metals and nonmetals like to form compounds with each other. These compounds are called ionic compounds. When two or more nonmetals bond with each other, they form a covalent compound.
Metalloids:
Physical Properties of Metalloids:
- Solids
- Can be shiny or dull
- Ductile
- Malleable
- Conduct heat and electricity better than nonmetals but not as well as metals
