Name ____________________________ Block _________ Date ________________________
Understanding the Atom & Elements and Chemical Bonds
Atom _____________________________________________________________________________
 The atom is made up of ________ main parts
 Nucleus ________________________________________________________________________
________________________________________________________________________
o Contained in the nucleus: ______________________ and ___________________
o Proton - ___________________________________________________________
 Size:______________________
 Charge: _____________________
 Location: ______________________
 Atomic Mass Unit (amu): ____________________
o Neutron - __________________________________________________________
 Size:______________________
 Charge: _____________________
 Location: ______________________
 Atomic Mass Unit (amu): ____________________
 Electron Cloud ________________________________________________________________________
________________________________________________________________________
o Contained in the electron cloud: ___________________________
o Electron - __________________________________________________________
 Size:______________________
 Charge: _____________________
 Location: ______________________
 Atomic Mass Unit (amu): ____________________
Contributor
Democritus
Aristotle
John Dalton
J.J. Thomson
Ernest Rutherford
James Chadwick
Niels Bohr
Your research:
Contribution
Elements
 __________________________________________________________________________
__________________________________________________________________________
 __________________________________________________________________________
__________________________________________________________________________
Find Carbon on the periodic table in the back of your textbook. Copy down a Carbon element
box inside the box below.
Atomic Number _____________________________________________________________________________
_____________________________________________________________________________
 Turn to the periodic table in your text book… can you find the atomic number in the
following element boxes?
o Oxygen_______
o Potassium _________
o Golf __________
Protons and Neutrons
 The number of ___________________ of the same element will always be
_____________.
 However, atoms of the same element can have ________________________________.
 For example: Every carbon atom has 6 protons, however some have 6, 7, OR 8
neutrons.
 When atoms of the same element have different numbers of neutrons they are called
____________________.
 Isotope –
________________________________________________________________________
 Most elements have ______________________ isotopes.
Mass Number - ________________________________________________________________
Average Atomic Mass – _________________________________________________________
_____________________________________________________________________________
 The average atomic mass is _________________ and based on each isotope’s
_________________________________________________.
 Approximately 99% of Earth’s carbon is __________________ which is why on the
periodic table carbon’s average atomic mass is close to 12 (12.01).
The arrangement of Elements
 Elements were originally arranged by _________________________________________
 Elements are arranged in order of ____________________________________________
 The word “Periodic” _______________________________________________________
________________________________________________________________________
The Periodic Table
 The three main regions of elements on the periodic table classify elements as
________________________________________________________
 Columns
o The ______________________ (up and down) columns of the periodic table are
called _______________________.
o There are _________________________ groups.
o Elements in the same group or family have __________________________________
 Rows
o The horizontal rows of the periodic table are called _____________________
o Elements in a period _____________________________________________
o The first element in a period is usually an active ________________, and the last
element in a period is always an inactive ________________________.
o Atomic number (number of protons) _______________________________________
o Atomic mass (number of protons + neutrons) ________________________________
_____________________________________________.
o Metals are on the _______________________
o Non-metals are on the ______________________.
On the following periodic table.
o Number the groups 1-18 and label “groups”
o Number the periods 1-7 and label “periods”
Energy Levels
o Different electrons within an atom have _______________________________________
o An electron moves AROUND the nucleus at a distance that corresponds to ___________
____________________________
o Electrons ____________________ to the nucleus have the __________________
amount of energy.
o Electrons _____________________ from the nucleus have the ________________
energy.
o Negatively charged _________________ are strongly attracted to ____________
charged nucleus of an atom.
o The OUTERMOST electrons can easily be attracted to the nucleus of ________________
_____________________
o We call these OUTERMOST electrons ___________________________________
o Valence Electron - ________________________________________________________
_______________________________________________________________________
o These attractions are what causes __________________________.
How to determine the number of Valence Electrons each element has
o The number of _______________________ in each atom of an element can help
determine _______________________________________________________________
o The exception to finding number of valence electrons is __________________________
o Group 1 has _________
o Group 2 has _________
o Group 3-12 __________
o Group 12-18 The number of valence electrons is equal to the ones digit of the
group number:
o Group 13__________
o Group 14 __________
o Group 15__________
o Group 16__________
o Group 17 __________
o Group 18 __________
o **HELIUM is the exception and has ________ valence electrons