1. The Atom, Standard Notation and Bohr-Rutherford Diagrams
Grade 10 Academic Science
Cardinal Ambrozic C.S.S.

2. The Atom LOCATION Electron Proton Neutron ORBITS
Maximum number of electrons in the 1st orbit/ shell is 2
Maximum number of elecrons in the 2nd and 3rd orbit/shell is 8
NUCLEUS
This is where most of the mass is
Electron
(negatively charged)
Proton
(positively charged)
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms
Neutron
(neutral:
no charge)

3. Orbits around the nucleus
Subatomic Particles
Subatomic Particle
Symbol
Charge
Relative Size
Relative Mass
Location
Proton p+ +1
Large 1
Nucleus
Neutron n0
Electron e- -1
Very Small
Orbits around the nucleus
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms

4. Standard Atomic Notation
The atomic structure of an element may be represented by the following notation:
Mass Number
(Rounded Atomic Mass) Z X
Element Symbol A
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms
Atomic Number

5. Formulas to use when Drawing Atoms
ATOMIC NUMBER
# of PROTONS =
This is also equal to the number of electrons in a NEUTRAL atom. Therefore,
ATOMIC NUMBER = # of PROTONS = # of ELECTRONS
MASS NUMBER
(rounded Atomic Mass)
# of PROTONS
# of NEUTRONS
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms = +
Therefore the number of neutrons is?
# of NEUTRONS = MASS NUMBER - # of PROTONS

6. Example Questions
1. In standard notation, nitrogen would be written as:
How many protons, neutrons and electrons does nitrogen have?
2. In standard notation, sodium would be written as:
How many protons, neutrons and electrons does sodium have?
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms

7. Information from the Periodic Table
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms
Remember that the mass number is the atomic mass rounded to the nearest whole number

8. Example Problem 3 Element Name Element Symbol Atomic Number
Atomic Mass
Mass Number
Standard Notation
# of Protons
# of Electrons
# of Neutrons
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms

9. Al K S Example Problem 3 Al 13 27 14 K 19 39 20 S 16 32 26.98 39.10
Element Name
Element Symbol
Atomic Number
Atomic Mass
Mass Number
Standard Notation
# of Protons
# of Electrons
# of Neutrons
Aluminum Al 13
26.98 27 14
Potassium K 19
39.10 39 20
Sulfur S 16
32.07 32 27 Al 13 39 K 19
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms 32 S 16

10. Bohr-Rutherford Diagrams
Using Bohr-Rutherford diagrams is a useful way of representing the first 20 elements. Draw the Bohr- Rutherford diagram for Lithium and Chlorine. Before you begin, write each element in standard notation.
Questions:
How many orbits does each of the above elements have?
What is the period number (row in the periodic table) for each of the above elements?
This is obviously a false assumption. We now know through experimental evidence that matter is composed of atoms