Atomic Structure And Periodic Table Flashcards
What did jj Thompson discover and what did it leed him to come up with
Electrons
Plum Pudding model
Describe the plum pudding model
A ball of positive charge with electrons embedded in it like currants in a plum pudding
Ehat did Ernest Rutherford design in 1909
Alpha particle scattering experiment
How did the alpha particle scattering experiment prove that the plum pudding model was wrong
The alpha particles were fired at thin gold foil
Most went through but some scattered in different directions
Describe the nuclear model
The mass of the atom is concentrated at the centre ( nucleus)
Nucleus is positively charged
What order were electrons protons and neutrons discovered
Electron proton neutron
Describe the structure of the atom today
A central nucleus with protons and neutrons in it
Surrounded by electrons in shells
What is the atomic number ( bottom number)
Number of protons in the atom
And atom contains equal numbers of
Protons and neutrons
What is the mass number ( top number)
Total number of protons and neutrons
To calculate number of p
Neutrons in atom
Mass number - atomic number
Isotopes are
Elements that have the same atomic number but a different mass number
( same amount of protons, dif amount of neutrons)
How to calculate reletive atomic mass of isotopes
Total number of atoms
What did dimitri mendeleev do
Created first periodic table which had gaps and showed elements with similar chemical properties lined up in groups
What is a period and how are they ordered
The horizontal rows in periodic table in order of increasing atomic number and increasing amount of shells
What are groups and how are they ordered
Elements placed in vertices columns in periodic table, ordered in the amount of electrons in their outer shell
Metals ______ electrons in chemical reactions making the __________ ions
Loose
Positive
Non metals _______ electrons so become ____________ ions
Gain
Negative
Properties of metals (5)
Conducts heat and electricity
Shiny
High density
Malleable
Ductile
Properties of non metals (4)
Poor conducted of heat and electricity
Dull
Low density
Brittle
Another name for group 0
Noble gasses
Going down group 0 the …
Atoms become larger
Intermolecular forces become stronger
Attractive forces between atoms become stronger
More energy is needed to overcome these forces
Are the noble gases boiling points low or high
Low
Why are the noble gasses inert ( extremely unreactive)
They already have full outer shells so they are stable and don’t need to share electrons
What is another name for group 1
Alkali metals
Physical properties of group 1
Soft
Relatively low melting points which get lower as you go down the group
Low density
Alkali metals + water =
Metal hydroxide and hydrogen
For alkali metals the reactivity of the elements …
Increases when you go down the group
Alkali metals + oxygen =
Metal oxide
Alkali metals + chlorine
Metal chloride
Concerning trends in reactivity, when you go down group 1
Atoms become larger
Outer electron shell become futher away from nucleus
Force of attraction between nucleus and outer electon lessen
Outer electron lost more easily
Another name for group 7
Halogens
properties of halogens going down the group
Higher melting / boiling points
Bigger molecules
Intermolecular forces become larger
More energy needed to overcome these forces
What are the halogens
Simple molecules
Metal + halogen =
Salt
In group 7 the reactivity…
Decreases as you go down
Halogen + non metal =
Compound
A ____________ halogen can replace a ____________ halogen
More reactive
Less reactive
Concerning trends in reactivity, going down group 7
Atoms become larger
Outer shell becomes futher from nucleus
Force of attraction between nucleus and outer shell lessens
Outer shell electron gained less easy
Halogen becomes less reactive
