Chapter 3, Elements and the Periodic Table
Section 1, Organizing the Elements
Atomic Structure
Matter is made up of atoms
- all atoms contain three subatomic particles
-protons
- found in the nucleus (center) of the atom
- positive (+)charge
- mass of one
neutrons
- found in the nucleus (center) of the atom
- no charge
- mass of one
electrons
- found on the outside of the nucleus of the atom
- negative (-) charge
- mass of 1/1835
To find out how the parts of an atom were discovered click here. (This link will be activated next week.)
-atoms are electrically neutral
number of protons (+)= number of electrons (-)
-atomic number of an element
- is the number of protons in an element
-is used to identify an element
-atomic mass of an element
- is the number of protons + number of neutrons
- it is also called the mass number
# of neutrons = atomic mass - atomic number
Play this game (click here) to practice finding the numbers of subatomic particles in each element
Organizing the elements
- all elements are organized into a periodic table
- there are over 115 elements
Now label this diagram like the one above.
Symbols:
shorthand way to write element names
-first letter in a symbol is a capital
- second letter in a symbol is lower case
example:
Co is the element cobalt
CO is the compound carbon monoxide
Element symbols to know:
Write the names and symbols of elements with atomic numbers1-20. Be careful to make the symbols correctly.
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Then find these elements in the periodic table and write their symbols in ths space provided:
iron _____ copper _____ silver _____
gold _____ iodine _____ nickel _____
uranium ___ tin _____ mercury _____
lead _____
Play this flash card game online.
Now make flash cards so that you can learn the symbols of the thirty elements listed above.
Organization of periodic table
columns are families or groups
- elements in a group have similar properties
example:
group 18 contains the noble gasses which rarely form compounds with any other element
rows are periods
- elements are arranged in a period according to atomic number
- properties change as you move across a row
-rows begin with metals ------>non metals -----------> noble gasses
Diagram of periodic table:
Liquids : -- mercury which is a metal and bromine which is a nonmetal
Gasses: hydrogen, helium,nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton,xenon, radon which are all nonmetals
Solids: all other elements
Valence electrons
-are electrons on the outside edge of atoms
- react with electrons from other atoms to form compounds
For information on individual elements click here.
Section 2, Metals
For the rest of Book K, chapter 3 notes click here
(These notes will be available after the homework assignment on this section has been completed.)