The Periodic Table - Unit 1 Topic 6 Flashcards
(34 cards)
Who first created a table of elements?
Newlands
How did Newlands organise elements in order?
Increasing atomic mass
What was Newlands’ table of elements called?
Why?
Newlands’ Octaves
Similarities between each 8th element
How did Mendeleev create his periodic table?
Wrote information about each element on a card and arranged them in piles with similar properties.
How did Mendeleev organise his periodic table?
Increasing atomic mass
How many elements did Mendeleev have?
63 elements
What are the differences between Mendeleev’s table and ours? (nowadays)
No gaps
Noble gases
Actinides & lanthanides
Elements in increasing atomic number
How many elements are there now?
118 elements
What are the similarities between Medeleev’s table and ours?
Separate metals & non-metals
Arranged in groups & periods
How do atoms change across a period?
Why?
Decrease in size
Extra positive charge as extra electron is added, shells pulled closer to nucleus with extra attraction.
Metal + water ->
Metal hydroxide + hydrogen
Metal + oxygen ->
Metal oxide
Metal + acid ->
Salt + hydrogen
Metal + halogen ->
Metal halide
What group are alkali metals?
Properties of alkali metals (down group)
Group 1
Bigger atoms
More reactive
Denser & softer to cut
Lower melting & boiling point
Why are atoms more reactive? (down the group - alkali)
Electrons are further away from the nucleus so they can leave more easily & react/bond.
Why do atoms become larger? (down group - alkali)
More layers
What group are alkaline earth metals?
Properties?
Group 2
Bigger atoms
More reactive
Denser & softer to cut
Lower melting & boiling point
4 things you would observe when potassium reacts with water?
Fizzes
Gives off hydrogen
Moves across surface & disappears
Burns with lilac flame
3 things you would observe when sodium reacts with water?
Melts into ball & disappears
Gives off hydrogen
Floats on surface
Why do atoms have similar properties?
Their atoms have the same amount of electrons in the outer shells.
Formula for half equations?
Metal -> metal + electron
Non-metal + electron -> Non-metal ion
Where are the transition metals?
In the middle
What group are the halogens?
Properties? (up group)
Group 7
Smaller atoms
More reactive
More soluble
More reactive
Lower melting & boiling point
