C2- The Periodic Table Flashcards
How did John Dalton arrange the elements on the periodic table in 1808?
In order of atomic mass
How did John Newlands arrange the elements on the periodic table in 1864?
In order of atomic mass and but started a new row every eight elements (law of octaves) as he notices the properties every eighth element was similar
Why did scientist not accept John Newlands’ ideas on the periodic table ?
- Because his law of octaves only worked up to calcium then broke apart
- some boxes had 2 elements in them
- he was not well-known/ respected scientist
How did Dimitri Mendeleev arrange the elements in the periodic table?
Arranged the 50 discovered elements in atomic mass but arranged them so that a periodic (regular occurring) pattern could be seen.
He left gaps
Why did Mendeleev leave gaps?
To make sure that elements with the same properties stayed in the same group, including the undiscovered ones
Whats did the discovery of the structure of the atom in the early 20th century show about the periodic table ?
That elements were in order of atomic (proton) number
What did the discovery of isotopes help explain about the periodic table?
The oddly heavy atomic mass of elements
Whats the max number of electrons in the first shell of an atom?
2 electrons
What do the number of electrons in an atoms outermost shell determine?
Its chemical properties
Whats does the group number tell us about the atoms structure?
The number of electrons its outer most shell
Do non metals gain or lose electrons
Gain
Do metals lose or gain electrons
Lose
Why are the noble gases (group 0) inert?
Don’t react with much as they have a full outermost shell
Periodic pattern
A regularly occurring pattern
What happens do the reactivity of the alkali metals (group1) as they go down the group?
Increases