The periodic table Flashcards
How many elements were known when Mendeleev arranged them?
Just over 60
How did Mendeleev arrange the periodic table?
In order of atom mass
How did Mendeleev line up the elements?
In groups with similar properties
How many elements are there as of 2014?
114
How many periods are on the periodic table?
Seven
How many groups are on the periodic table?
Eighteen
What are the positions of elements on the periodic table linked to?
Their physical and chemical properties
How are the elements ordered on the periodic table?
In order of increasing atomic number
How are elements in a group similar?
Each element has atoms with the same number of outer-shell electrons and similar properties
What do periods on the periodic table represent?
The number of the highest energy electron shell in an element’s atoms
What is periodicity?
The repeating trend in properties of the elements across the period
What is the periodic trend in electron configuration across a period?
Each period starts with an electron in a new highest energy shell
Period 2 - 2s subshell fills with 2 electrons, then 2p with 6
Period 3 - same pattern repeated for 3s and 3p subshells
Period 4 - although 3d subshell is involved, the highest shell number is 4, but only 4s and 4p are occupied
For each period, the s and p subshells are filled in the same way - periodic pattern
What is the periodic trend in electron configuration down a group?
Elements in each group have atoms with the same number of electrons in each subshell
What are blocks on the periodic table?
The elements in the periodic table are divided into blocks corresponding to their highest energy subshell
What are the 4 blocks of the periodic table?
s, p, d, f
