periodic table Flashcards
1
Q
early attempts
A
arranging by atomic weights
elements with similar properties in groups
some spaces have two elements in it
noble gas were unknown- due to odorless colourless
left spaces for unknown substances
2
Q
prediction
A
the gaps left
the properties of the elements next to gap revealed the missing one
later scientists use predictions of properties
3
Q
pair reversal
A
iodine has a lower atomic mass than tellurium , but similar properties to chlorine and bromine .
4
Q
modern periodic table
A
elements arranged in rows called periods in increasing atomic number
elements w/ similar properties are placed in columns = groups
