Unit 9B- Recall Questions- The periodic table Flashcards
Before Mendeleev, how did scientists attempt to classify elements?
By ordering them by their atomic mass
When scientists ordered elements by their atomic masses, what problem did they face?
Some elements were placed in inappropriate groups because not all had been discover
How did Mendeleev originally organise the periodic table?
By the atomic mass and the properties of the elements
How did Mendeleev’s ordering of elements help?
He left gaps which predicted the existence and properties of undiscovered elements
How is the periodic table organised today?
In order of atomic number with elements sharing similar properties in groups
What is the relationship between the atomic number of an element and its position in the periodic table?
As you go from left to right and move down the periodic table, the atomic number gets larger
What does the group number tell you about the structure of an atom?
Group number = number of electrons in outer shell
Apart from the number of electrons in the outer shell, what else do elements in the same group have in common?
Similar chemical properties
What does the period number tell you about the structure of an atom?
Period number = number of shells around an atom
Where are non-metals found in the periodic table?
Top right hand corner
How does the atomic structure of metals relate to their position in the periodic table?
Metals have only have 1, 2 or 3 electrons in their outer shell and therefore are found in groups 1, 2 or 3 on the left
