Periodic table Flashcards
What did Doberiener notice?
he noticed that elements could be grouped into triads - three elements that have similar properties
who were the three scientists who contributed in the making of the periodic table?
Doberiener , Newlands and Mendeleev
what was the problem with Doberiener’s method?
Not all elements had the same properties
What was Newland’s idea?
He arranged the elements in atomic weight and noticed that every 8th element have similar properties
what was the problem with Newland’s idea?
It only worked for the first 20 elements
What were the 2 key ideas Mendeleev produced?
- elements with with similar chemical reactivities and similar properties were grouped together in columns called groups
- Elements arranged in atomic weights (some exemptions)
Why did Mendeleev’s idea work?
He used his table to predict elements that were yet to be discovered
if an atomic structure has 1,2,3,4 electrons on the outer shell what is it?
It is a metal
if an atomic structure has 5,67,8 electrons on the outer shell what is it?
It is a non metal
how do metals and non metals react?
Metals react by losing electrons
non- metals react by gaining electrons
are the oxide of metals acidic or alkaline?
alkaline
what group are the noble gases in?
They are in group 0
why are noble gases unreactive?
because they have a stable arrangements of electrons - a full outer shell
Most abundant noble gas?
Argon- makes up 1% of the atmosphere
why are noble gases in their group?
The outer shell is full so they have to have another shell with 0 in
