PeriodicmtBle Flashcards
Why are the noble gases called nobel gases
There unreactive and have a stable arrangement of electrons
What is the boiling points like for the nobel gases as you go down the group
Boiling points of the nobel gases increase as you go down
Because they increase in size as they gain more shells meaning they have a stronger structure to break
Whats the reactivity of the alkalin metals as you go down the group
Increase as you go down
Because atoms get larger and valence shells get further from the nucleus causing a weakened attraction
How is the reactivity like in the nobel gases
Decrease
What is density
How concentrated something is
How could you tell sometning is low density in a liquid
If it floats
How do reactive elements react with water
Explosively
DescribE a metallic bond
Electrostatic attraction between delocalised outer shell electrons. Occurs in metals,
electricity conductivity is good in solids and liquids
Describe ionic bomds
Electrostatic attreaction between oppositely charged ions. Occurs in metals and nonmetals
Poor in solids,
Good in liquids, acids
Descrobe covalent bonds
Electrostatic attraction between a shared pair of electrons and the nuckei of 2 atoms. Occurs in non metals
Electrical comductivity is poor with everything
What things are found in a metallic structure
Delocalised outer shell electrons
Lattice positive ions
Defention of metalic bond
The electrostatic forces of attraction between delocalised outer shell electrons and lattice positive ions
What was john daltons atom beliefs
Atoms were tiny sohere of the same matter that couldnt be divided
What is the plum pudding model
A spherical cloud of positive charges
Who made the plummpudding model
JJ Thompson in 1897, after discoverint the electron
What was the alpha scatter experiment
Feoger Marsden Rutherford in 1908-1913, fired alpha particles at very thin gold foil observing some alpha particles were deflected from the middle showing there was a great center of mass
Whats the nuclear model
A model of an atom with a tiny positive nucleus surrounded by emoty space
What was the Bohr model
A nuclear model proposing electrons orbit the nucleus in fixed shells or orbitals located at a set distance from the nucleus
Who discovered that electrons were organised in shells
Bohr 1913 in his nuclear model
What was the order of discovery of atomic structure
Electrons
Protons
Neutrons
Relative charge of protons neutrons and electrons
+1
0
-1
Relative mass of P N E
1
1
1/2000
Why is it called the periodic table
Because it is arranged in periods
Why is group 1 reactive
The reactivity of Group 1 elements increases as you go down the group because: the atoms get larger. the outer electron gets further from the nucleus. the attraction between the nucleus and outer electron gets weaker – so the electron is more easily lost and react more
What did Johann Dobereiner notice
Elememts with similar chemical properties often occured in threes, called triads
Who discovered every eigth element reacted in a similar war
John Newlands
Who discovered elements with similar properties often occured in threes
Johann Dobereiner
What was the problem with Newlands octives
Sometimes elements were grouped together with totally dofferent properties
When dod the modern periodic table get created and by who
1896 Dimitri Mendeleev
Why did Mendeleev leave gaps in his table
For elements that hadmt been discovered yet
2 ways mendeleevs table is different from today
Ordered by atomic weight as protons hadnt been discovered, group zero hadnt been discovered then
Whats wrong with ordering the periodic table in atomic weight
Elements can appear in the wrong order due to the presence of iscotopes
What did the alpha scatter experiment show
As most alpha particles went straight through, atoms were made up mostly of empty space however the center of the atom must have a positive charge and contain a great deal of mass
Who discovered neutrons
1932 chadwick
What is the outer layer of a shell called
Valence shell
Why is alkaline mteals called that
Because when reacted with water create alkalines
Why is alkaline mteals called that
Because when reacted with water create alkalines
Why is alkaline mteals called that
Because when reacted with water create alkalines
