- element - pure substance found in nature; cannot be broken down any further chemically; represented by a letter-symbol (K, Pb, Uut)
- knowing the position of the element in the table (group - up & down; period - left & right) can tell you about its chemical properties
- elements are divided into three groups, metals, nonmetals, and metalloids
- metals:
- usually on the left side of the periodic table
- usually shiny solids
- are good conductors of heat/electricity
- are solid at room temperature (except for Hg; liquid)
- nonmetals:
- located on the right side of the table
- not usually shiny
- are poor conductors of heat/electricity
- can be liquid/solid/gas at room temperature
- metalloids:
- located on the solid line that starts at B (boron) and angles to At (astatine)
- have intermediate properties
- represented by only seven elements
- metals:
- writing chemical formulae - give back what they give to you; write atomic symbol and write the number of atoms in subscript; one is never used in subscript - just do the symbol by itself
- finding subatomic parts:
- atomic number = number of protons = number of electrons
- atomic mass (rounded) - number of protons = number of neutrons
- every atom of a given element has the same atomic number
sep 19 2013 ∞
feb 10 2015 +
feb 10 2015 +