Periodic Table Worksheet

The Periodic Table

Periodic table: ­­visual arrangement of elements that provides users with quick information about the elements

• Periods: ­­horizontal rows on the table
• Groups: vertical columns on the table

Atomic symbol: 1 or 2 letter abbreviation of the element name

• allows us to write shorthand/quickly

Atomic number: number of protons in the nucleus of an atom

• Atomic number defines the element (is ALWAYS the same for given element)
• CANNOT change without changing what the element is

Ion: atom of the same element that has a different number of electrons than other atoms of that element

• Atoms are usually neutral (same number of electrons as protons)
• Atoms can gain/ lose electrons, giving the atom a charge (+ or -­)
  ○ +ion means lost electrons
  ○ ­-ion means gained electrons

Isotope: atom of the same element that has a different number of neutrons than other atoms of that element

• Some exceptions may have more/less neutrons

Mass number= number of protons + number of neutrons

 
*Atomic Mass/ Atomic Weight: average mass of atoms of an element (average mass of all isotopes of an element)