CC4 Periodic Table Flashcards
What is the atomic number of an atom?
The number of protons in an atom
What can the period tell you about the electrons in an atom?
How many shells an atom has. E.g. carbon is in the second period so has two shells
Why did Mendeleev put some elements in groups?
Because they had similar chemical properties (e.g. they reacted violently with water)
What did Mendeleev put the elements in order of?
Increasing atomic mass
How is the modern periodic table organised?
In order of increasing atomic number
Why did Mendeleev leave gaps in his periodic table?
For elements that had not been discovered yet
What are groups in the periodic table?
The columns, numbered 1, 2, 3, 4, 5, 6, 7, 0
What can the group tell you about the electrons in an atom?
How many electrons in the outer shell. E.g. carbon is in group 4 so has 4 electrons in the outer shell
How are the electrons arranged in atoms?
Orbiting the nucleus in shells
Where are the metals found on the periodic table?
on the left hand side
How many electrons does calcium have?
20 (same as atomic number!)
How many electrons does silicon have?
14 (same as atomic number!)
How are the electrons in sulphur arranged?
2.8.6 (18 electrons total)
How are the electrons in magnesium arranged?
2.8.2 (12 electrons total)
How many electrons are in the outer shell of boron?
3 (it is in group 3!)
How many electrons are in the outer shell of phosphorous?
5 (it is in group 5!)
How many electrons are in the outer shell of sodium?
1 (it is in group 1!)
An element has three shells and three electrons in the outer shell. What element is it?
Aluminium (group 3, period 3
How many electrons are in the outer shell of Gallium?
3 (it is in group 3!)
How many electrons can go in the first shell? How many in the second shell?
2 = 1st shell, 8 = second shell
How did Mendeleev predict the properties of the undiscovered elements?
He looked at the trend in the properties down the group and across the period that the element was in.
