C1 - Periodic Table and Development

how he organised his table:

• systematic way based on weight of each element 

newland's law of octaves:

• intervals of 7 often separated elements with similar chemical properties.
• he made the mistake of trying to force elements into this pattern

problems with his table:

• more than one element in each box (very different properties)
• no space for new or undiscovered elements 
• in order to fit his law of octaves, elements with very different properties had to go in the same box 

how he ordered the elements:

• in order of their weight
• placed elements with similar properties in the same group 

not accepted at first because:

• had to swap elements around so that they were in groups
• gaps in the table
• 2 elements in the same box in some instances 
• hi upbringing and social status

more widely accepted because:

• elements that were placed in groups all had similar properties
• newly discovered elements fitted correctly in the gaps that he had left

based on electronic structure 

ordered by the number of protons in each element, which results in elements with similar properties being grouped together 

found in the middle of the periodic table, and have similar properties which are very different to those of group one. the melting points of transition metals are higher than group one,for example

much less reactive

much denser, stronger, and harder than group 1

compounds:

transition metal compounds are colourful, while group 1 compounds are usually white

transition metals can have different ion charges (different numbers of electrons)

catalysts

trans metals can be used as catalysts in reactions. this means they speed up the chemical reaction but do not get used up