C2.4 Groups in the Periodic Table Flashcards
How can elements and compounds be classified?
Ionic
Simple Molecular Covalent
Giant Molecular Covalent
Metallic
What is the melting and boiling point of ionic bonding?
High
Ionic substances are solids at room temperature
What is the solubility of ionic bonding?
Many dissolve in water
Does ionic bonding conduct electricity?
Conducts electricity when molten or in solution
What are the melting and boiling points of simple molecular covalent bonding?
Low - They are liquids and gases at room temperature
What is the solubility of simple molecular covalent bonding?
Some dissolve in water
Does simple molecular covalent bonding conduct electricity?
Doesn’t conduct electricity
What are the giant molecular covalent bonding melting and boiling points?
High - Solids at room temperature
What is the solubility of giant molecular substances?
Insoluble in water
Does giant molecular substances conduct electricity?
Doesn’t conduct electricity except from graphite
What are the properties of metallic substances?
Good conductor of heat and electricity Solids at room temperature Doesn't dissolve in water Malleable Held together by metallic bonds
What are atoms?
Smallest neutral part of element that can take part in chemical reactions
What are elements?
Substances that cannot he split up into simpler substances
What is a compound?
A substance containing two or more elements chemically joined together/combined
What are bonds?
Force of attractions between atoms or ions
What is Malleable?
Can be hammered into shape
What are metallic bonds?
Type of bonding in metals
What are transition metals?
Metal elements located in the central block of the periodic table
What are the structure of metals?
A regular arrangement of positive ions surrounded by a sea od delocalised electrons
What are the properties of metals?
Limited to malleability
Can conduct electricity
What are most metals?
Transition metals
What are the properties of transition metals?
High melting point
Forms coloured compounds
What are delocalised electrons?
Free electrons that can move around between ions in a metal or in layers of graphite
What are Alkali Metals?
Elements found in group 1 of the periodic table
What are the properties of alkali metals?
Soft
Low melting points
What is the word equation for alkali metals?
Metal + water Metal hydroxide + hydrogen
How does lithium react with water?
Floats on surface and fizzes but gradually disappears as reaction proceeds
How does Sodium react with water?
Same as Lithium but more powerfully and has a low melting point
How does Potassium react with water?
Same as Lithium and Sodium but even more powerfully and hydrogen catches fire producing a lilac flame
What is the reactivity of alkali metals as you go down the group?
The reactivity of alkali metals increases as you go down the group
What are the patterns in alkali metals?
Electrons increase further down the group (same with electron shells)
This means that the outer electrons are further from the nucleus
Force between positive and negative charges are greatest when charges are close together
What is reactivity?
How fast an element reacts
What are Halogens?
An element in Group 7 of the periodic table
What are the properties of Fluorine?
Pale Yellow colour
Gas at room temperature
What are the properties of Chlorine?
Yellow-Green colour
Gas at room temperature
What are the properties of Bromine?
Brown colour
Liquid
What are the properties of Iodine?
Grey colour
Solid
What are the reactions of halogens with metals?
Similar reactions
Produce metal halides
What is the word equation to produce halides?
Metal + Halogen Metal Halide
What is a Halide?
A compound formed between a halogen and another element (EG - metal or hydrogen)
What is produced when halogens react with hydrogen?
Hydrogen Halides which dissolve in water to form acidic solutions
What are Displacement Reactions?
A reaction where a more reactive element takes place of a less reactive element
Which Aqueous solution does Fluorine react with?
Metal Chloride
Metal Bromide
Metal Iodide
Which Aqueous solution does Chlorine react with?
Metal Bromide
Metal Iodide
Which Aqueous solution does Bromine react with?
Metal Iodide
What is the definition of Noble Gases?
Elements in Group 0 of the periodic table
What are Noble Gases compared with other elements?
Chemically inert
Why is it difficult to get Noble Gases to react?
All elements in Group 0 have full outer electron shells
Which chemists discovered Noble gases and what did they do?
Lord Rayleigh (1842 - 1919):
He measured the densities of different gases
But then he noticed that the density of pure nitrogen made in chemical reactions were less than the density of nitrogen made from air by removing gases
Sir William Ramsay (1852 - 1916)
He heard about the results and hypothesised that nitrogen made from air also contained a gas
Experiments were carried out to test hypothesis and discovered Argon (gas) and helium
He later found Neon, Krypton and Xenon
What are the uses and properties of Noble Gases?
Inertness - Welding uses an inert gas to stop the hot metal reacting
Low Density- Helium has a low density and it’s used for filling balloons and airships
Non-Flammability - Argon is used in fire-extinguishing systems because it’s non-flammable
What physical properties are used to estimate unknown values for Noble Gases?
Boiling Point - Increases as you go down the group
Density - Increases as you go down the group
What does inert mean?
Does not react