Transcript Our modern Periodic Table

2.2
The Periodic Table
Origin Of The Periodic Table
a) Chemists in the 19th century wished to organize elements
b) Attempts focused on grouping elements with similar properties
c) In 1867, Dimitri Mendeleev found patterns in the elements and
organized them into a table
d) The resulting table had holes for elements not yet discovered
Let’s take a look at the very first attempts of organizing the periodic
table …some look soooo different to today’s periodic table!
Early symbols
Meyer's Spiral periodic table of 1872
1886
Crookes'
Periodic Table
Our modern Periodic Table
THE MODERN PERIODIC TABLE
Organized according to ATOMIC number --- by
Mendeleev
The properties of the elements repeat/recur periodically
when the elements are arranged in increasing order by their
atomic numbers
Our modern Periodic Table
The Periodic Table provides information
on the physical and chemical properties of elements
Atomic Mass - mass of average
atom
Atomic Number - number of protons
Ion Charge - electric charge that
forms when an atom gains or loses
electrons
Trends in the Periodic Table:
The periodic table organizes the elements by
vertical columns (___________) and horizontal
rows (______________).
The elements are arranged depending on the
chemical and physical properties of elements
in repeated patterns and increasing atomic
masses.
THE PERIODIC TABLE
Metals, Non-metals, Metalloids
See page 55
Periods and Families
1) Each horizontal row in the periodic table is a period
2) Vertical columns form groups or chemical families
Zoom in on Families
Vertical columns form groups or chemical families
a)
Alkali metals - highly reactive group 1
metals
b) Alkaline earth metals - group 2, burn
in air if heated, reactive metals
c)
Halogens - group 17, highly reactive
non-metals
d)
Noble gases - group 18, stable and
unreactive non-metals
Try:
For Sulphur, give the following information:
•
•
•
•
Atomic number:
Average atomic mass:
Ion charge:
Symbol of element:
• Protons?
Homework:
Worksheet 2.2