Possible Questions Flashcards
What was Robert Boyle’s contribution to science?
He gave the first accurate definition of an element
Define an element.
An element is a substance that cannot be split into simpler substances by chemical means
Who gave the first accurate definition of an element?
Robert Boyle
What was Humphry Davy’s contribution to science?
He discovered potassium, sodium, calcium, barium, strontium and magnesium by passing electricity through compounds containing these elements
Who discovered a range of elements by passing electricity through compounds?
Humphry Davy
What was Johann Dobereiner’s contribution to science?
He arranged the elements as triads e.g. chlorine, bromine and iodine
Give an example of a Dobereiner triad.
Chlorine
Bromine
Iodine
Define a triad
A triad is a group of three elements with similar chemical properties in which the atomic weight/relative atomic mass of the middle element is approximately equal to the average of the other two
Who arranged the elements in triads?
Johann Dobereiner
What was John Newland’s contribution to science?
John arranged the elements in order of increasing atomic weight and noticed that the properties seemed to repeat with every eight (Newland’s Octaves)
What are Newland’s Octaves?
Newland’s Octaves are arrangements of elements in which the first and the eight element, counting from a particular element, have similar properties
Who arranged the elements in octaves?
John Newland
What was Mendeleev’s contribution to science?
He arranged the elements in order of increasing atomic weight and placed elements with similar properties under each other in groups, leaving gaps.
Define Dmitri Mendeleev’s Periodic Law.
When elements are arranged in order of increasing atomic weight the properties of the elements recur periodically, i.e. the properties displayed by an element are repeated at regular intervals in other elements
Who was the first to leave gaps in their table when arranging the elements according to increasing atomic weight?
Dmitri Mendeleev
