History of the Periodic Table- Unit 3

HideShow resource information
In the early 1800s what could they only go on?
Atomic Mass
1 of 16
What were the two obvious ways to categorise elements?
Their physical and chemical properties or their relative atomic mass
2 of 16
What happened in the 20th century?
After protons and neutrons were found that people realised elements were best arranged in the order of atomic number
3 of 16
Back then what was the only thing they could measure?
Relative atomic mass- so known elements were arranged in order of atomic mass
4 of 16
Where is the name 'periodic table' from?
A periodic pattern was noticed in the properties of the elements
5 of 16
What was the first good effort?
Newland's Law of Octaves
6 of 16
Who created Newlands' law?
A man called Newlands- he arranged things more usefully in 1864
7 of 16
What did Newlands notice?
Every eight elements had similar properties so he listed some of the known elements in rows of seven
8 of 16
The set of eight was called what?
Newlands' Octaves
9 of 16
Why did the pattern break down on the third row?
Transition metals like titanium and iron messed up and it was because there was no gaps left that he was ignored
10 of 16
Newlands' ideas were presented to the chemical society in 1865, so why was his work criticised?
His groups had elements that didn't have similar properties, he mixed up metals and non-metals and he didn't leave any gaps for elements that hadn't been discovered yet
11 of 16
Who left gaps and predicted new elements?
Dmitri Mendeleev
12 of 16
What did Mendeleev do in 1869?
Arranged 50 known elements into his table of elements and he included gaps too
13 of 16
Mendeleev put the elements in order of what?
Atomic mass
14 of 16
Why did he leave gaps?
To keep elements with similar properties in the same vertical columns (groups) and he left very big ones in the first two rows before the transition metals came in on the third row
15 of 16
Why were the gaps clever?
They predicted undiscovered elements- when the elements were found and fitted the pattern it was good for Dmitri
16 of 16

Other cards in this set

Card 2

Front

What were the two obvious ways to categorise elements?

Back

Their physical and chemical properties or their relative atomic mass

Card 3

Front

What happened in the 20th century?

Back

Preview of the front of card 3

Card 4

Front

Back then what was the only thing they could measure?

Back

Preview of the front of card 4

Card 5

Front

Where is the name 'periodic table' from?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Elements, Water, and Organic Chemistry resources »