Physical Properties
Define atomic radius
The distance from the nucleus of an atom to the outermost shell of said atom.
What are Tetrachlorides?
Tetrachlorides are chemical compounds that contain one atom of an element bonded to four chlorine atoms.
This group of elements all have an ns² np² outer electron configuration.
What is Group IV?
CO₂ reacts with NaOH to form this salt.
What is sodium carbonate (Na₂CO₃)?
This term describes oxides like SnO₂ and PbO₂ that can behave as both acids and bases.
What is amphoteric?
How many valence electrons are present on their valence shell?
Four
General formula for tetrachlorides
The general formula for tetrachloride is Ecl4, where the E represents the element.
This effect explains why heavier Group IV elements prefer the +2 oxidation state because the s-electrons remain tightly held.
What is the inert pair effect?
The bonding in CO₂ and SiO₂ is primarily this type.
Covalent bonding
Two uses of ceramics based on silicon (vi) oxide (sio2)
1. Glass and Glassware
2. Ceramics and Porcelain
3. Refractory Materials
Used for furnace linings and kiln bricks because SiO2 can withstand extremely high temperatures without melting.
4. Electronics and Semiconductors
5. Optical Fibres
Define the screening effect
The screening effect, (or shielding effect) which is when inner electrons block or reduce the pull of the nucleus on the outer electrons, increases.
The full inner orbitals shield the outer orbitals from increasing nuclear charge.
State the formula and use for Carbon tetrachloride
CCl₄
Used as a solvent (but toxic if inhaled).
The +4 oxidation state becomes less stable as you move in this direction down Group IV.
What is down the group / from carbon to lead?
SiO₂ reacts with NaOH to form this compound.
sodium silicate (Na₂SiO₃)?
Which substance has a giant covalent structure with strong Si–O bonds that give it high melting point, hardness, chemical inertness, and thermal stability, making it widely used in ceramics?
Silicon(IV) oxide / SiO₂
State 4 Group IV elements
Carbon, Silicon, Germanium, Tin, and Lead
What is the white solid is formed when titanium tetrachloride reacts with water?
titanium dioxide (TiO₂)?
These electrons are poorly shielded by d-orbitals, causing them to be held tightly by the nucleus.
Answer: What are the s-electrons?
The basic character of Group IV oxides changes in this direction down the group.
increases
Stability of Oxides and Aqueous Cations in High vs Low Oxidation States
higher oxidation states form acidic oxides, are unstable in water, act as strong oxidizers, and are associated with positive E° values. Lower oxidation states form basic or amphoteric oxides, are more stable as aqueous cations, act as strong reducers, and are associated with lower or negative E° values.
State 2 elements, their melting point and what type of conductor they are
Diamond has a melting point of 3730°C. No free electrons are present hence it is a non-conductor of electricity.
Graphite sublimes. However, it is a good conductor.
Silicon has a melting point of 1410°C and is known to be a semi-conductor.
Germanium has a melting point of 937°C and is also a semi-conductor.
Tin has a melting point of 232°C and exists in the form of two allotropes: Grey and White Tin. Grey Tin is a semi-conductor while white tin is a good conductor of electricity.
Lead has a melting point of 237°C and is a good conductor of electricity
These types of tetrachlorides behave as strong Lewis acids: metal or non-metal?
What are metal tetrachlorides?
Because removing four electrons requires extremely high ionization energy, Group IV elements form this type of bonding instead of forming M⁴⁺ ions.
What is covalent bonding
Because CO₂ and SiO₂ react with alkalis, their oxides demonstrate this acid/base behaviour.
What is acidic behaviour?
Because removing four successive valence electrons requires extremely high ionization energy, no Group IV element forms this ion in the solid state, causing all of them—from carbon to lead—to bond primarily through covalent interactions instead.
What is the X⁴⁺ ion?