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Flashcards in history of periodic table Deck (12)
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1
Q

in the 1800s what were the two ways of categorising elements?

A
  • physical and chemical properties

- relative atomic mass

2
Q

what did they have no idea about in the past?

A

protons and electrons

3
Q

newlands law of octaves?

A
  • in 1864 every 8th element had similar properties
  • the pattern broke down on the third row with titanium and iron
  • left no gaps
4
Q

why was newlands law of octaves criticised?

A
  • groups had elements with different properties in (carbon and titanium)
  • mixed non metals and metals together
  • didn’t leave gaps for undiscovered elements
5
Q

dimitri mendeleev

A
  • in 1869 he put elements in order of atomic mass
  • but he left gaps for elements with similar properties in same vertical group
  • when new elements were found they fitted the pattern
6
Q

the modern periodic table

A
  • electron with a high energy level is easily lost as there is less attraction
  • high energy level elements are less likely to gain electrons as there is less attraction from they nucleus
7
Q

as you go down the column, group 1 metals are…

A

more reactive

8
Q

as you go down the column, group 7 elements are…

A

less reactive

9
Q

what did mendeleev do that was convincing?

A

he left gaps which newly discovered elements fit into perfectly

10
Q

what did they discover in the late 19th century?

A

protons, neutrons and electrons. the periodic table matches well.

11
Q

in the modern periodic table how are elements arranged?

A

by their electronic structure which predicts their chemical properties

12
Q

when is attraction less?

A

when there are a lot of inner electrons, as they get in the way of nuclear charge also known as shielding