How do we use matter?
Distinguish between the terms ‘group’ and ‘period’
Periods are the horizontal rows of the periodic table. Periods are determined by the number of the electronic shell which a neutral atom consists of.
The vertical columns of the periodic table, for example, noble gases. Groups are determined by the number of electrons in the outermost shell or the valence electrons. (often transition metals are ignored when discussing valence electrons and groups, for example, group 7 is actually the 17th row)
Identify the relationship between the electronic arrangement of elements & their position in the periodic table up to Z=20
The period or the row in which the element is positioned in the periodic table refers to the number of electronic shells in its electronic configuration.
The group or the column in which the element is positioned in the periodic table refers to the number of valence electrons in the neutral atom or the number of electrons in the outermost shell. (this pattern excludes transition metals)
These periods and groups are indicated by the electronic configuration of the neutral atom.
Identify the relationship between the number of electrons in the highest occupied energy level for an element & its position in the periodic table
The group or the column of the atom is determined by the number of valence electrons or the number of electrons in the outermost shell in a neutral atom. (this pattern excludes transition metals)
Describe the properties of metals & non-metals
Suggest how metallic bonding explains the properties of metals
Solid metals have a lot of atoms arranged in a regular structure and hence creating a giant structure of atoms. These atoms lose their outermost electrons and become cations while sharing their electrons (known as the delocalized electrons) with each other in the metal. This results in electrostatic force between the positive cations and negative electrons, which holds everything together in a regular structure and provides metal with its typical properties. This bond between the metal’s atoms is known as metallic bonding.
Strength and MP & BP
The strong electrostatic forces give the metal its strength due to great attraction between the subatomic particles, furthermore, this also increases the MP and BP since greater energy/heat is required to overcome the Intermolecular forces. Therefore, most metals are solid at room temperature and very strong.
Conductivity of electricity and heat:
The delocalized electrons are able to carry the electricity and thermal energy and heat, therefore, metallic structures are good conductors of heat and electricity due to these delocalized electrons which are not found in other nonmetals.
Malleable and ductile:
Despite the strength of metallic structures due to the electrostatic force, metals can still be easily bent or hammered into shapes as well as drawn into wire, this is because the metallic structures are often in a regular pattern and thus layers can be slid over one another and thus they are not as fixed.
Outline how metals can be extracted in relation to the reactivity series
The reactivity series is a series of metal elements, and sometimes carbon and hydrogen, that is arranged according to their reactivity from highest to lowest. Even though hydrogen and carbon are not metals, they are helpful in determining the exact method of extraction as well as helpful indicators for comparison.
Extraction is the process where metals are acquired from the different ores, these methods often vary from the types of metal that are being extracted, the reactivity series aids us in determining the ideal method of extraction depending upon its reactivity.
Metals can be extracted in two ways electrolysis and reduction. Elements above carbon can be extracted through electrolysis, while elements below carbon can be acquired via reduction. Although gold and platinum are native and thus do not require extraction.
In order to extract metals above carbon, electrolysis is required, this is when the different ionic compounds with opposite charges attract to their respective charged electrodes. Thus the two different ions can be separated and the specific metal can be acquired. Although, the initial rock/ore must be melted before electrolysis could be conducted.
- place pieces of ores in a crucible and heat over a Bunsen burner until it melts
- insert two carbon electrodes into the molten electrolyte and pass a direct current between them
Note: Carbon electrodes are chosen because they have a high melting point and are inert (they will not react with the reactants and products during electrolysis).
It is easy to predict the products of electrolysis of molten electrolytes because they simply split into their elements:
- The metal is formed at the negative electrode because that is where the positive metal ions are attracted
- The non-metal element is formed at the positive electrode where the negative non-metal ions are attracted
Often ores are usually oxides, sulfates, carbonates of a certain element, in order to acquire the element itself it is necessary to displace the less reactive element with a more reactive one through a single displacement reaction. This occurs when the metal is replaced by another element higher than itself on the reactivity series. The other material which displaces the metal is known as the reductant which often is carbon in the form of charcoal, this ensures that it already is more reactive than the metal otherwise reduction wouldn’t have been chosen.
- Place the pieces of the ores, or your oxide/sulfate/carbonate into a crucible with a reductant and heat it over a Bunsen burner for a while.
- Immediately pour the contents into a beaker of cold water
- Drain the water with charcoal contents and rinse with water again.
- Repeat the previous step several times
- Finally, drain the water and collect the metal particles at the bottom of the beaker.
Note: reduction only occurs for the metal which loses the oxygen, whereas, oxidation occurs for the reductant which gains an oxygen element. In real life, a blast furnace is utilized to heat the ore, while the gases/the slag is later removed.
Outline the properties of the following groups:
- Groups 1 & 2: electrical conductivity & malleability
- Group 7: State at room temperature; reactivity with metals
- Group 8: Inert
Outline the periodic trends for groups 1, 2, 7 & 8:
- Atomic size
- Boiling & melting points
Deduce the ions formed when groups 1, 2, 3 loose electrons
- Group 1 elements form cations with a 1+ charge
- Group 2 elements form cations with a 2+ charge
- Group 3 elements form cations with a +3 charge
- Groups 1,2,3 always produce cations
Deduce the ions formed when groups 5, 6, 7 gain electrons
- Group 5 elements form anions with a -1 charge
- Group 6 elements form anions with a -2 charge
- Group 7 elements form anions with a -3 charge
- Groups 5,6,7 always produce anions
State that transition elements can form more than one ion, including examples
Transition elements can form more than one ion since the valency often differs in transition elements with no strict number, therefore some transition metals may produce ions with different charges. For example, Au (valence electrons: 1), will produce a cation with a +1 charge, whereas Ni (valence electrons: 2) will produce a cation with a +2 charge.