2. Atomic Structure d

3. Atomic Structure d Electron (negative) Neutron (neutral)
Proton (positive) d
nucleus

4. Atomic Number, Z
All atoms of the same element have the same number of protons in the nucleus, Z 13
Atomic number Al
Atom symbol
26.981
AVERAGE Atomic Mass

5. Mass Number, A Mass Number (A) = # protons + # neutrons
C atom with 6 protons and 6 neutrons is the mass standard
= 12 atomic mass units
Mass Number (A) = # protons + # neutrons
NOT on the periodic table…(it is the AVERAGE atomic mass on the table)
A boron atom can have A = 5 p n = 10 amu

6. Isotopes
Atoms of the same element (same Z) but different mass number (A).
Boron-10 (10B) has 5 p and 5 n
Boron-11 (11B) has 5 p and 6 n
10B
11B

7. Two isotopes of sodium.

8. Learning Check
Naturally occurring carbon consists of three isotopes, 12C, 13C, and 14C. State the number of protons, neutrons, and electrons in each of these carbon atoms.
12C C 14C
#p+ _______ _______ _______
#no _______ _______ _______
#e- _______ _______ _______

9. Answers
12C C 14C #p
#no #e

10. Periodic table can be found in your planner!
7.    For each of the positive ions listed in column 1, use the periodic table to find in column 2 the total number of electrons that ion contains. The same answer may be used more than once.
Column 1 Column 2
____ 1. Al+3 A. 2  
____ 2. Fe+3 B. 10
____ 3. Mg+2 C. 21
____ 4. Sn+2 D. 23  
____ 5. Co+2 E. 24   
____ 6. Co+3 F. 25   
____ 7. Li+1 G. 36  
____ 8. Cr+3 H. 48  
____ 9. Rb+1 I. 76    
____ 10. Pt+2 J. 81  
Periodic table can be found in your planner!
Look at element
Look at atomic #
Add or subtract the charge given
Find answer

11. Periodic table can be found in your planner!
7.    For each of the positive ions listed in column 1, use the periodic table to find in column 2 the total number of electrons that ion contains. The same answer may be used more than once.
Column 1 Column 2
_B__ 1. Al+3 (13-3 = 10) A. 2  
____ 2. Fe+3 B. 10
____ 3. Mg+2 C. 21
____ 4. Sn+2 D. 23  
____ 5. Co+2 E. 24   
____ 6. Co+3 F. 25   
____ 7. Li+1 G. 36  
____ 8. Cr+3 H. 48  
____ 9. Rb+1 I. 76    
____ 10. Pt+2 J. 81  
Al 13-3 = 10
Answer would be B
Periodic table can be found in your planner!
Look at element
Look at atomic #
Add or subtract the charge given
Find answer

12. Periodic table can be found in your planner!
7.    For each of the positive ions listed in column 1, use the periodic table to find in column 2 the total number of electrons that ion contains. The same answer may be used more than once.
Column 1 Column 2
_B__ 1. Al+3 (13-3 = 10) A. 2  
_D__ 2. Fe+3 (26-3=23) B. 10
____ 3. Mg+2 C. 21
____ 4. Sn+2 D. 23  
____ 5. Co+2 E. 24   
____ 6. Co+3 F. 25   
____ 7. Li+1 G. 36  
____ 8. Cr+3 H. 48  
____ 9. Rb+1 I. 76    
____ 10. Pt+2 J. 81  
Periodic table can be found in your planner!
Look at element
Look at atomic #
Add or subtract the charge given
Find answer

13. IONS
IONS are atom that has gained or lost an electron and now has a positive or negative charge.
Taking away an electron from an atom gives a CATION with a positive charge
Adding an electron to an atom gives an ANION with a negative charge.
To tell the difference between an atom and an ion, look to see if there is a charge in the superscript! Examples: Na+ Ca+2 I- O-2
Na Ca I O

14. Forming Cations & Anions
A CATION forms when an atom loses one or more electrons.
An ANION forms when an atom gains one or more electrons
F + e- --> F-
Mg --> Mg e-

15. GROUP TIME!

16. The Periodic Table