atomic structure + the periodic table Flashcards
Define malleable.
The ability of a metal to be formed into different shapes.
Define ductile.
The ability of a material to stretch and deform permanently.
Define brittle.
When a material fractures, breaks or snaps.
What 4 physical processes separate mixtures?
~Filtration
~Crystallisation
~Simple and fractional distillation
~Chromatography
What are mixtures?
2 or more elements or compounds that are not chemically combined.
What is the mass number?
Total number of protons and neutrons.
What is the atomic number?
The number of protons in an atom of an element.
What is the relative atomic mass an average of?
The abundance of isotopes of the element.
How do you calculate relative atomic mass?
(Isotope 1 mass x abundance) + (Isotope 2 mass x abundance) divided by 100
How is a compound formed or separated?
From elements and by chemical reactions.
What is the electronic structure?
When electrons occupy the lowest available energy levels/shells closest to the central nucleus.
John Newlands ordered his periodic table by…
Atomic weight (+the law of octaves)
What is law of octaves?
That similar properties occurred every 8th element.
When did the law of octaves stop working?
After calcium.
Dmitri Mendeleev ordered his periodic table by…
Atomic mass.
How is the current periodic table arranged?
Elements are in order of atomic number.
Elements with similar properties are…
In the same group.
Elements in the same group have the same amount of…
Electrons in their outer shell.
Metals react to form…
Positive ions.
Non metals do not…
Form positive ions.
When were electrons, protons and neutrons discovered?
In the early 20th century.
What disproved the order of atomic weight?
Knowledge of isotopes.
How many electrons do group 1/ alkali metals have in their outer shell?
1.
What happens to reactivity as you go down group 1?
It increases.
What do group 1/alkali metals react with water to form?
An alkaline solution and hydrogen.
What do the group 1/alkali metals react with oxygen to form?
An oxide.
What do the group 1/alkali metals react with chlorine to form?
A white precipitate.
What happens when lithium reacts with oxygen?
A red flame and white solid is produced.
What happens when lithium reacts with water?
It fizzes and gradually disappears.
What happens when lithium reacts with chlorine?
A white powder is produced.
What happens when sodium reacts with oxygen?
An orange flame and white solid is produced.
What happens when sodium reacts with water?
It melts, fizzes and disappears quickly.
What happens when sodium reacts with chlorine?
Yellow flame and clouds of white powder are produced.
What happens when potassium reacts with oxygen?
A lilac flame is produced.
What happens when potassium reacts with water?
Produces sparks and a lilac flame then disappears.
What happens when potassium reacts with chlorine?
There is a more vigorous reaction than sodium.
How many electrons do the group 0/ noble gases have in their outer shell?
8 (full).
Which noble gas is an exception?
Helium as it only has 2 electrons in its full outer shell.
What increases going down the group in group 0/ noble gases?
The boiling points and relative atomic mass.
Why are the group 0 elements/ noble gases unreactive?
They have a stable electron arrangement meaning they don’t form molecules easily.
What are transition elements like compared to group 1 elements.
~Much less reactive
~Are harder and stronger
~Higher melting points and density (except for mercury)
What is manganese used as a catalyst for?
The decomposition of hydrogen peroxide.
What is iron used as a catalyst for?
The haber process.
What is nickel used as a catalyst for?
The manufacture of margarine.
What are the typical properties of transition metals?
~Useful as catalysts
~Form coloured compounds
~Have ions with many different charges
What are the properties of chromium?
Lustrous, brittle and hard metal.
What are the properties of manganese?
Hard and very brittle, difficult to fuse, easy to oxidise.
What are the properties of copper?
Highly ductile and conductive, malleable and soft.
What are the properties of cobalt?
Brittle and hard with a high melting point.
What are the properties of nickel?
Hard, malleable and ductile, decent conductor of heat and electricity.
What are the properties of iron?
Good conductor, rusts easily in air and is strong,ductile and malleable.
How many electrons does group 7/ the halogens have in their outer shell?
7.
What forms when the group 7 elements/ the halogens react with metals?
Ionic compounds.
What forms when the group 7 elements/ the halogens react with non metals?
Covalent compounds with a shared pair of electrons.
What increases as you go down group 7/ the halogens?
~Relative molecular mass
~Melting and boiling point
Why does reactivity decrease down group 7/ the halogens?
~As halogens react by gaining an electron
~Number of shells increase so less other electrons are attracted
A decrease in reactivity in group 7 / the halogens means…
A more reactive halogen can displace a less reactive halogen in the aqueous solution of its salt.
