History of the periodic table

Question 1

Robert Boyle + definition of an element

Answer 1

An element is a substance that cannot be split into simpler substances by chemical means

Question 2

Humphrey Davy

Answer 2

Discovered elements through electrolysis = potassium, sodium and magnesium

Question 3

Dobereiner-triads

Answer 3

Groups of 3 elements
Arranged by similar chemical properties
Atomic weight of the middle equals the average of the other 2=Li,Na,K

Question 4

Mendeleev

Answer 4

Arranged atomic weight
Left gaps for undiscovered elements
Switched Te and I to suit the chemical properties

Question 5

Mosley

Answer 5

Discovered the atomic number
Validated Mendeleev for switching Te and I

Question 6

Atomic number

Answer 6

Number of protons

Question 7

Atomic weight

Answer 7

Number of protons and neutrons

Question 8

Relative atomic mass

Answer 8

The average mass of an isotope taking into account their natural abundances compared to 1/12 of the mass of a C-12 isotope

Question 9

Isotope

Answer 9

Atoms of the same element but with different mass because of the different number of neutrons

Question 10

Newlands octaves

Answer 10

Arranged in increasing atomic weight. Properties of every 8 element recurred periodically