Chapter C2 The Periodic Table Flashcards
What did John Dalton strange the periodic table by?
Atomic weight
What does the group number tell you?
The number of electrons in the outermost electron shell
What did newlands recognise?
The properties of every eighth element were similar
What did Mendeleev do?
First correct periodic table, arranged by atomic weight and with regularly occurring patterns, with spaces
What is the difference between metals and non mental?
Metals conduct electricity, and are ductile and malleable
Non metals are insulators and are brittle
What are the noble gases?
Elements with a stable electronic structure of eight electrons in their outermost shell
What is the exception to the noble gases?
Helium
What happens to the boiling point as you go down the noble gases?
It gets higher
What is a group?
A vertical column in the periodic table
What is a period?
A horizontal row of the periodic table
What group is known as the alkali metals?
Group one
What group is known as the noble gases?
Group eight
Name properties of group one
Very reactive (have to be stored in oil) as there is only one electron
Reactivity increases as you go down the group
Have a low density compared to other metals
Very soft
Silvery, shiny surface - this fills quickly as a layer of oxide forms
Form a metal ion with a +1 charge
What is the melting and boiling points like for group 1?
Relatively low temperatures for metals
As you go down the group it gets lower
What happens if you react group one with water?
Fizzes to form hydrogen gas
What happens if you put potassium in water?
Ignites- burns with a lilac flame
Why are group one called the alkali metals?
When reacting with water, they form a hydroxide
This hydroxide is soluble in water, and turns purple if it’s ph is tested
How do alkali metals react with non metals?
React vigorously- producing metal chlorides which are white solids
What happens when you put a metal chloride formed from group one and a non metal in water?
It dissolves to form a colourless solution
What is group seven known as?
The halogens
What are properties of group seven?
Low boiling and melting points which increase as you go down
Poor conductors of heat or electricity
Get less reactive as you go down the group
What charge do the group seven elements form?
-1
What charge do the group one elements form?
+1
What is the rule with halogens?
The more reactive halogen will displace the less reactive halogen from solutions of its salts
What displaces all other halogens?
Fluorine
What effects does the number of shells occupied by electrons have?
Larger atom lose electrons more easily going down a group
Or
Larger atoms lose electrons less easily going down a group
Why does more electron shells affect the atom?
The outer electrons are further away from the positively charged nucleus
The inner shells screen or shield the nucleus
Why is the reactivity trend as it is in group one?
The outer electron is shielded from the nucleus by the other shells
The outer electron is further away from the nucleus
Therefore the outer electron is more easily removed as you go down the group and so gets more reactive
What are the properties of the transition metals?
Good conductors Hard and strong High densities High melting points Shiny Conducts
Can the transition elements be used as catalysts?
Yes
What is different about the transition metals to other groups?
Can create ions with different charges
What kind of compounds do transition elements form?
Coloured compounds
Name examples of coloured compounds
Iron oxide- red
Manganese chloride- pink
Chromium chloride- purple
Uses of transition metals
Jewellery
Wires
Saucepans
Colours of transition metals
Copper- blue
Iron 2- light green
Iron 3- orange brown
Cobalt- blue
