Atomic Sctructure And The Periodic Table Flashcards
What is the definition of an element?
A substance consisting of atoms with the same atomic number
What is the definition of a compound?
A substance containing two or more different types of atoms chemically joined together
What is the definition of a mixture?
A substance containing different types of elements and compounds that are NOT chemically joined together
What types of substances does paper chromatography separate?
Different dyes in an ink
What type of substance does filtration separate?
Insoluble solids from liquids
What type of substance does evaporation separate?
Soluble solids from solutions
What type of substance does crystallisation separate?
Soluble solids from solutions
What two separation techniques are used to separate rock salt?
Filtration and crystallisation
What type of substance does simple distillation separate?
A liquid from a solution
What type of substance does fractional distillation separate?
A mixture of liquids
What can fractional distillation do that simple distillation cannot?
Separate multiple liquids with similar boiling points
Who described atoms as solid spheres and when?
John Dalton at the start of the 19th century
Who created the plum pudding model and when?
J. J. Thomson in 1897
Who conducted the alpha particle experiments in 1909 and created the nuclear model (and also named the proton in 1927)?
Ernest Rutherford and Ernest Marsden
Who proposed that electrons orbit the atom in fixed shells and when?
Niels Bohr in 1913
Who proposed the existence of the neutron and when?
James Chadwick in 1932
What is the order of the amount of electrons allowed in each shell?
2, 8, 8
In the early 19th century, what were elements categorised by?
1) Their physical and chemical properties
2) Their relative atomic mass
Who made the first periodic table with gaps and when?
Dmitri Mendeleev in 1869
How did Mendeleev sort his periodic table?
Mainly by atomic mass, but changed it if the properties contrasted
What is the name of the vertical columns on the modern periodic table that contain elements with similar properties?
Groups
What does the group number tell you?
How many electrons are in the outer shell of each element
What are the rows in the modern periodic table called?
Periods
Where on the modern periodic table do elements not have many electrons in the outer shell, so react to lose these electrons easily?
The left
Where on the modern periodic table do elements have lots of electrons in their outer shell, so try to gain or share electrons to get a full outer shell?
The right
What are some properties of metals?
Strong, malleable, shiny, good conductors of heat and electricity, high boiling and melting points, high density
What are some properties of non metals?
Brittle, dull looking, bad conductors of heat and electricity, low melting and boiling points, low density
In Group 1, does the reactivity increase or decrease as you go down the group?
Increase - outer electron is more easily lost because it is further away from the nucleus so its attraction is less
In Group 1, do the melting and boiling points increase or decrease as you go down the group?
Decrease
In Group 1, does the relative atomic mass increase or decrease as you go down the group?
Increase
What kind of ions do alkali metals form when they react with non-metals?
1+
What do alkali metals produce when reacting with water?
Hydrogen gas and metal hydroxides
What do alkali metals produce when reacting with chlorine?
White metal chloride salts
What do alkali metals produce when reacting with oxygen?
Metal oxides
True or false - alkali metals are very soft
True
