Periodic Table and its Development Flashcards
The elements in the periodic table are arranged in order of ______/_______ number
Atomic/proton
The columns in the table are called ____________
Groups
The rows in the table are called _____________
Periods
What occurs to justify it being called the periodic table?
similar properties in the elements occurring at regular intervals
Electrons in the same ________ in the periodic table have the same number of ____________ in their __________ shell and this gives them similar ____________ properties
Group
Electrons
Outer
Chemical
Group 1 are called the _____________ metals
Alkali
When Group 1 elements react with water, what can you expect to see in the reaction?
Tarnishing quickly
Fizzing/setting alight
Producing an alkali
Group 1 are the __________ reactive and Group 8 are the ___________
Most
Least
How were elements classified before the discovery of protons, neutrons and electrons?
In order of their atomic weights
The early periodic tables were _____________ and some elements were placed in the wrong _________ if the strict order of atomic weights was followed
Incomplete
Groups
How did Mendeleev overcome the problem of putting elements in the wrong place on the table?
By leaving gaps for undiscovered elements
What was discovered to explain why the order based on atomic weights was not always correct?
Isotopes
