OCR GCE Chemistry - Periodic Table

In 1880s, how were elements grouped?

-Atomic mass

 

How were elements categorised?

-Physical and chemical properties, and Relative Atomic Mass

 

How is the modern periodic table arranged?

-Proton number

 

Why was it difficult at the time to arrange the periodic table by proton number?

-Protons and electrons were not known, they could only measure relative atomic mass

 

In 1817, who attempted to group similar elements?

-Johann Döbereiner

 

What were Johann Döbereiner’s groups called?

-Triads

 

Which 3 elements did he notice had similar properties?

-Halogens

 

Who was John Newlands? What did he do/notice?

-If he arranged elements in order of mass, similar elements appeared at regular intervals – every eighth element was similar. Known as octaves

 

Who created the first accepted version of the Periodic Table in 1869?

-Dmitri Mendeleev

 

How did Dmitri Mendeleev’s periodic table differ from John Newlands?

-Left gaps in the table where next element didn’t seem to fit

 

What was the advantage of Dmitri Mendeleev leaving gaps?

-Keeping elements with similar chemical properties in the same group

-Predicting properties of undiscovered elements in the gaps

 

How was Dmitri Mendeleev proved right?

-When elements were later discovered (germanium, scandium, gallium) with properties that matched Mendeleev’s predictions

 

Who made the MODERN periodic table in 1914?

-Henry Moseley

 

How did Henry Moseley arrange his elements?

-Atomic number

-Noble gases added (Group 0)

 

What was the final big chance by Glenn Seaborg?

-Suggested how the f-block elements fit into the Periodic Table

 

In the modern Periodic Table what represents to the rows and columns?

-Period (row)

-Group (column)

 

What is the similarity of all elements in the same period?

-Same number of electron shells (if you don’t worry about the sub-shells)

 

How many electron shells do the elements in Period 1?

-1

 

What is the similarity of all elements in the same group? What does this mean?

-Same number of electrons in their outer shell

-Similar physical and chemical properties

 

How many electrons in the outer shell of Group 4 atom?

-4

 

How many ‘block’s, can the periodice table be split into? What are they?

-4

-s, p, d, f

 

Is 2p⁶ a complete sub-shell? Why?

-Yes

-Only 6 electrons occupy a p sub shell

 

What does periodicity mean?

-Trends that occur (in physical and chemical properties) across periods?

 

What name is given to trends that occur across periods in terms of physical and chemical properties?

-Periodicity

 

Metal to non-metal is a trend that occurs going **** to ***** in each period?

-Left to right

 

Name a factor that decreases across a period

-Atomic radius

 

Why does atomic radius decrease across a period?

-As the number of protons increases, the positive charge of the nucleus increases. Electrons are pulled closer to the nucleus, making atomic radius smaller

 

Name a factor the increases across period

-Ionisation energy

 

Why does ionisation…