1. The Atom Contains 3 subatomic particles:
Neutron – nucleus particle with no charge.
- can vary within an element - ISOTOPES.
Proton – nucleus particle with a positive charge.
Electrons – negative particles move in specific orbits.
- e- jump/drop orbits releasing energy.
- same # of positive and negative
charges = neutral.

2. ELEMENT - a fundamental pure substance that cannot be broken down into simpler parts.
Atoms contain 3 subatomic particles:
Neutron (no) – nucleus particle with no charge.
Proton (p+) – nucleus particle with positive charge.
Electrons (e-) – negative particles in orbits.

3. Bohr Diagrams
and
Atomic Information

4. Describe the terms atomic number and atomic mass number.
State the charge, location, and mass of the subatomic particles.
Draw the Bohr model of atoms.
Key Words
Bohr model Periodic table
Atomic mass Atomic Number
Valence electrons

5. All these new elements needed names and symbols.
Symbols originated from a Greek or Latin name
Element
Modern Symbols
Alchemist Symbols
Dalton Symbols
Antimony Sb
Arsenic As
Bismuth Bi
Carbon C
Copper Cu
Gold Au
Iron Fe
Lead Pb
Mercury Hg
Silver Ag
Sulpher S
Tin Sn
Zinc Zn

7. + - A proton has a mass of 1 atomic mass unit (μ).
Since the neutron is the same size, it is also 1 μ.
Electrons are considered zero mass (too small).
All unreacted atoms are neutral - number of protons and electrons are the same.
Neutrons +
Protons -
electrons

8. The units of Atomic mass are amu OR μ.
The atomic mass is equal to the total mass of the protons and neutrons in the nucleus
The units of Atomic mass are amu OR μ.

9. No TWO elements have the same number of protons.
Heavier elements have a bigger nucleus – more protons (and neutrons).
No TWO elements have the same number of protons.

10. Proton number is used to identify an element.
The number of protons in an element does NOT change.
Proton number is used to identify an element.
The number of protons in the nucleus of an element is called the atomic number.

11. 4 – 2 = 2 Number of Protons Atomic Number Number of Neutrons
Atomic Mass – Atomic Number
Number of Electrons
Number of protons (Atomic Number)
4 – 2 = 2

12. Sulfur (S)
How many protons are there in one atom of Sulfur?
Atomic number p+
How many electrons in one atom of Sulfur?
Atoms are neutral e-
How many neutrons in one atom of Sulfur?
Atomic mass = 16 no
How many protons in 3 atoms of Sulfur?
3 x 16 = 48 p+

13. Potassium (K)
How many protons in one atom of Potassium?
Atomic number is 19 – 19 p +
How many electrons in one atom of Potassium?
Atoms are neutral – 19 e -
How many neutrons in one atom of Potassium?
At mass – At number 39 – 19 = 20 no
How many protons in 10 atoms of Potassium?
10 x 19 p + = 190 p +

14. Atomic Information
and
Bohr Diagrams

15. All electrons found in the outer orbit are called VALENCE electrons.
Electrons begin filling the closest energy level to the nucleus first.
All electrons found in the outer orbit are called VALENCE electrons.

16. Lithium has an atomic number of 3.
Lithium has ONE Valence electron.

17. Drawing a Complete Bohr Atom
Determine the number of no, p+, e- in the atom.
Draw the nucleus.
Label the #of protons and neutrons in the nucleus
Add orbits and fill with the appropriate # of e-.
Nitrogen (N)
p+ : 7
no : 14 – 7 = 7
e- : 7
7p+
7no

18. Sodium (Na)
p+ : 11
no : 23 – 11 = 12
e- : 11
11p+
12no

19. Atom is made of protons, neutrons and electrons.
Electrons travel in orbits or energy levels around the nucleus (outer orbit – valence)
Atomic number is equal to the number of protons.
Atoms are neutral - number of protons and electrons is the same.
Atomic mass is the protons plus the neutrons