1. Introduction to atomic Particles
Inside the Atom

2. The Atoms Family

3. THE ATOM The atom is a particle in an element
The atom is composed of smaller particles called “sub-atomic particles”
Subatomic particle
Where is it found in the atom?
Charge
( + / - / 0)
Protons
Nucleus +
Neutrons
Electrons
Shells -

4. 1) Structure of the atom:
nucleus
Neutrons (0 charge) – have mass
Protons (+ charge) – have mass
Electron shell
Electrons (- charge) have almost no mass
Electron Shells:
- 1% of atom’s mass
- 99% of atom’s volume
Nucleus:
- 99% of atom’s mass
- 1% of atom’s volume

6. Chemical Symbols
A chemical symbol is an abbreviation of the name of an element
Chemical symbols always have one or two letters
The first letter is ALWAYS a capital
If there is more than one letter, the second letter is a small letter

7. H – hydrogen F - fluorine
O – oxygen C - carbon
N – nitrogen B - boron
Cl – chlorine He - helium
Ca – calcium Li - lithium

8. Chemical Formula
A chemical formula is the combination of symbols that represents a particular compound.
It indicates which elements are present and in what proportion
NaCl – Sodium Chloride
O2 – oxygen gas

9. Getting info from the Periodic Table
The periodic table has loads of information on it that you need to be able to find.
Most importantly
atomic number,
mass number,
element symbol,
and element name.

10. Atomic Number – the number of protons and electrons found in a
neutral atom 4 Be
Beryllium
9.0
Atomic Mass – the average
mass of an atom
(Protons + Neutrons)

12. .
The atomic number indicates the number of protons (or electrons) in that atom
The mass number represents the sum of protons and neutrons in that atom
Neutrons = mass # - atomic #

13. Determining number particles
Protons = atomic number
Electrons = atomic number
Neutrons = mass number – atomic number

14. Example: Sodium Atomic number = 11 Mass number = 23
Number of neutrons = 23 – 11 = 12
Note: the number of neutrons is either equal to or greater than the number of protons

15. Standard Atomic Notation
1. Write the symbol of the element
2. Write the mass number at the top left
3. Write the atomic number at the bottom left
Ex Magnesium
Ex Lithium 24 7 Li Mg 3 12

16. Standard notation
Example: Chlorine

18. Atoms and Shell Diagram Puzzle
Symbol
element
Atomic number
Atomic mass
# p
# e
# n 24 Mg 12
Magnesium
24-12=12 34 K 19
Potassium 34 19 19
34-19=15 19
Sodium 11 28 11 11 17
Chlorine

19. EXAMPLES Name Symbol Atomic # Atomic Mass #p #e #n Zinc Zn 30 65 35 1910 Ca N 28

20. Check it out! Overflowing fountains… Look for patterns…
Element builder

21. Drawing Bohr-R diagrams
Label # of p+ and n in the nucleus
Start filling electron energy levels (shells) from the nucleus
1st level – Maximum 2 electrons
2nd level – Maximum 8 electrons
3rd level – Maximum 8 electrons

22. Ex. Fluorine 19 F 9 Protons: same as atomic number = 9
Neutrons: mass number – atomic number = 19 – 9 = 10
Electrons: same as atomic number = 9

23. Ex. Magnesium – S.A.N. and Bohr Rutherford
12p+
12 n 24 Mg 12
Protons: same as atomic number = 12
Neutrons: mass number – atomic number = 24 – 12 = 12
Electrons: same as atomic number = 12

24. Homework
Page 89 #1-2
Page 93 #1-8