development of the periodic table

Question 1

what were elements arranged by in the 1800s?

Answer 1

atomic weight

Question 2

who came up with their own table of the elements in 1869?

Answer 2

dimitri mendeleev

Question 3

how did mendeleev arrange his table?

Answer 3

mostly in order of atomic weight, but switched elements if the properties meant it should be changed

Question 4

why did mendeleev leave gaps?

Answer 4

for elements he thought hadn’t been discovered yet

Question 5

what did newly discovered elements help to confirm?

Answer 5

that Mendeleev was correct as they fitted the pattern

Question 6

what helped explain why the order of atomic weight was incorrect?

Answer 6

isotopes

Question 7

describe the early periodic tables

Answer 7

incomplete with some elements placed in incorrect groups

Question 8

similarities between newlands and mendeleevs table

Answer 8

-both arranged in order of atomic weight

Question 9

how did newlands arrange the elements?

Answer 9

in octaves of 7

Question 10

why was newlands work critiqued?

Answer 10

-some of his groups contained elements with no similar properties
-he mixed up metals and non-metals
-didn’t leave gaps for undiscovered elements

Question 11

what did mendeleev do different to newlands?

Answer 11

left gaps