The Periodic Table Flashcards
Revision (31 cards)
What is the main purpose of categorising and ordering substances?
To understand and use them
What two ideas were prominent in the early categorisation of elements?
- Chemical properties of elements
- Atomic weight
Who developed the basis for the modern Periodic Table?
Dmitri Mendeleev
In the 1800s, how many known elements were there?
Around 60
What pattern emerged when elements were ordered by increasing atomic weight?
A roughly repeating pattern of similar chemical properties
Why are the ordered elements called a Periodic Table?
Because of the periodic repetition of properties
What did Mendeleev primarily order the elements by?
Increasing atomic weight
What did Mendeleev do when chemical properties suggested a different grouping?
He relaxed the ordering by atomic weight
What did Mendeleev predict about undiscovered elements?
He predicted their properties based on gaps in his table
What is the modern periodic table based on?
Increasing atomic/proton number
What do the columns of the periodic table represent?
Groups of elements with similar chemical properties
What do the rows of the periodic table represent?
Periods with the same number of electron shells
What is the electronic structure of an atom?
The arrangement of electrons in an atom
Which shell can hold a maximum of 2 electrons?
First shell
How many electrons can the second shell hold?
8
How is the electronic structure of sodium (atomic number 11) represented?
2,8,1
What is the relationship between electronic structure and the periodic table?
- Number of shells = Period number
- Number of electrons in outer shell = Group number
- Total electrons = Atomic number
What are the typical properties of metals?
- Good conductor of electricity
- Good conductor of heat
- Shiny
- High density
- Malleable
- Ductile
What are the typical properties of non-metals?
- Poor conductor of electricity
- Poor conductor of heat
- Dull
- Low density
- Brittle
Where are metals located on the periodic table?
On the left of a stepped line starting at B-Al-Si
What is the atomic structure characteristic of group 1 elements?
One electron in their outer shell
What is the atomic structure characteristic of group 7 elements?
Seven electrons in their outer shell
What is the boiling point trend in noble gases?
They all have low boiling points
What explains the inertness of noble gases?
They have complete outer shells
