1. Periodic Table
Trends

2. Russian scientist and professor
Mendeleev (1870)
Russian scientist and professor
Arranged the 63 elements by atomic mass
Noticed a repetition of properties (periodicity)
Called the pattern of properties “Periodic Law”
Mendeleev (correctly) predicted the mass of elements yet to be discovered and left spaces open for them

3. Repetition of properties (periodicity) became more clear
Moseley (1913)
Experiments showed proton number was a better method to organize the elements.
Repetition of properties (periodicity) became more clear
Modern Periodic Law:
“The properties of elements are a periodic function of increasing atomic number”
We know now that most element properties are due to the number of valence electrons

4. An updated Periodic Table containing ALL 118 elements – separated into metal and non-metal atoms make up EVERYTHING in the Universe.

5. Element with properties opposite to those of metals (brittle, dull…)
Rows of the periodic table are called periods.
Elements in periods do not have similar properties
Left to right
Elements change from metals to non-metals
Non-metal
Element with properties opposite to those of metals (brittle, dull…)
periods

6. Family names and locations need to be memorized
Columns of the periodic table are called groups.
Elements in groups have similar properties
A family is a group with a specific name:
Family names and locations need to be memorized
GROUP
Alkali metals
Alkaline Earth metals
Chalogens
Halogens
Noble (inert) gases

9. (make coloured compounds, speed up chemical reactions…)
Transition Metals: groups 3 – 12
unique properties different from group 1 and 2 metals
(make coloured compounds, speed up chemical reactions…)

13. Simplest atomic structure - only 1 e- and 1 p+
Hydrogen*
Group 1
Non-metal gas
1 valence electron
Simplest atomic structure - only 1 e- and 1 p+
Highly chemically reactive
The placement of hydrogen is only because of its structure - 1 proton… Sometimes a table will have it raised above the Alkali Metals to avoid confusion

14. Increasing Reactivity
The LESS electrons needed, the GREATER the chemical reactivity of the element
Increasing Reactivity

16. CAN YOU ANSWER THESE QUESTIONS? S1-2-06
How is the Periodic Table organized for the elements and what trends exist?
Vocabulary & Concepts 
Mendeleev Period Group
Family Alkali metals Earth metals
Transition Metals Chalcogens Halogens
Noble gases

17. IONS
IONS are atoms or groups of atoms with 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

18. 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-

19. PREDICTING ION CHARGES
In general
metals (Mg) lose electrons ---> cations
nonmetals (F) gain electrons ---> anions

20. Learning Check – Counting
State the number of protons, neutrons, and electrons in each of these ions. 39 K+ 16O -2 41Ca #p+ ______ ______ _______ #no ______ ______ _______ #e- ______ ______ _______

21. One Last Learning Check
Write the nuclear symbol form for the following atoms or ions: A. 8 p+, 8 n, 8 e- ___________ B. 17p+, 20n, 17e- ___________ C. 47p+, 60 n, 46 e- ___________

22. Charges on Common Ions -3 -2 -1 +1 +2
By losing or gaining e-, atom has same number of e-’s as nearest Group 8A atom.