C3.1.2 The modern periodic table Flashcards
1
Q
What did Henry Moseley propose?
A
That element should be ordered by atomic numbers instead of atomic mass.
2
Q
What effect did the new ordering system have on Mendeleev’s periodic table?
A
it allowed Mendeleev’s table to be refined into the modern periodic table.
3
Q
What scientific turning point led to Moseley’s proposition?
A
The discovery of neutrons, protons and electrons.
4
Q
What is a group?
A
A collection of elements with the same number of electrons in their outer shell - similar properties.
Vertical
5
Q
What is a period?
A
The number of occupied energy levels (shells).
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