The periodic table Flashcards
(8 cards)
How are the elements arranged?
In order of their atomic number so elements with similar properties are in the same group
Why is it called the periodic table?
Because similar properties occur at regular intervals
What are properties of the Group 1 elements?
The melting and boiling points decrease down the group.
They get more reactive down the group.
What are the properties of Group 7 elements?
Melting and boiling points increase down the group.
Decrease in reactivity down the group
How was the first periodic table arranged?
By atomic weights
What was wrong about arranging the periodic table by atomic weight?
The groups the elements were put into did not match their properties.
Who created the better periodic table?
Dmitri Mendeleev
How did people know that ordering by atomic weights was not right?
Isotopes were discovered
