Chemistry revision Flashcards
As you go down the periodic table, atomic radius increases, and as you go left to right it decreases, why?
The radius increases as you go down because
The radius decreases as you go left to right because the forces between nucleus and electrons increase as protons are added.
As you go down the periodic table the first ionisation energy decreases, and as you go left to right it increases, why?
This is because the outermost electron is, on average, farther from the nucleus, meaning it is held less tightly and requires less energy to remove.
As you go down the periodic table the electronegativity decreases, and as you go left to right It increases, why?
From top to bottom down a group, electronegativity decreases. This is because atomic number increases down a group, and thus there is an increased distance between the valence electrons and nucleus, or a greater atomic radius.
Describe a Linear economy
Traditional economic structures are Linear
-they increase demand for new sources of natural recourses
-produce wastage of recourses
How it works:
NATURAL RECOURCES> TAKE> MAKE> DISTRIBUTE> USE> DISPOSE
Describe a Circular economy
. Emerging economic structures are circular
-they reduce demand for new recources
-wastage is reduced by recycling and reuse
How it works:
NATURAL RECOURSES> TAKE> MAKE/REMAKE> DISTRIBUTE> USE/REUSE/REPAIR> SORT TRANSFER> RECYCLE/COMPOST/ENRICH> (does a loop)
What is a polar bond?
A polar bond is a type of covalent bond. A bond between two or more atoms is polar if the atoms have significantly different electronegativities (>0.4). Polar bonds do not share electrons equally, meaning the negative charge from the electrons is not evenly distributed in the molecule. This causes a dipole moment.
Intramolecular forces vs intermolecular forces
Intramolecular forces (strong) are those within the molecule that keep the molecule together, for example, the bonds between the atoms.
Intermolecular forces (relatively weak) are the attractions between molecules, which determine many of the physical properties of a substance
List the physical properties of intermolecular forces
List the types of intermolecular forces
.Dispersion force (Van der Waals)
. Dipole-Dipole interations
.Hydrogen ‘bonds’
Describe the intermolecular force: Dispersion force
Describe the intermolecular force: Dipole-Dipole interactions
Describe the intermolecular force: Hydrogen ‘Bonds’
metallic lattice model properties
Metals are:
.Hard
.Dense
.Has a high melting point.
=the attraction between the cations and tithe electrons hold them together tightly
.shiny (lustrous)
.Conducts heat well
.Conducts electricity well
=moving electrons carry charge(electricity) and energy (heat) while reflecting light
.Ductile (pull into wire)
.Malleable (beat into sheets)
=cations can be moved within the sea of electrons in response to physical forces
Ionic lattice properties
Ionic substances(salt) are:
.Hard
.Generally light
.high melting points
.Strong attraction between ions
=ions take up more space and leave gaps when placed together, making them lighter than pure metals
.Solids
.Will not conduct electricity
=ions are locked in place and no electrons can move in the solid
.generally poor heat conductors
=lightly packed ions can’t transfer heat very well
.once molten, conduct heat and electricity well
=once dissolved or molten charged particles can move and conduct electricity and heat
Gold a lustrous metal that can be beaten in a thin sheet used in the production of computer micro processes as it is a superior conductivity of electricity
A) explain the physical properties of gold using the metallic lattice model
A)
Gold is malleable as cations of gold are able to slide against each other as the metal is beaten into a thin sheet. Gold is lustrous and a good conductor of heat because it’s moving electrons carry charge (electricity)and energy (heat)while reflecting a lot (making it shiny)
Gold a lustrous metal that can be beaten in a thin sheet used in the production of computer micro processes as it is a superior conductivity of electricity
b) The drug Allochrysin is a gold (I) salt that is used to treat arthritis. It is administered with an injection. It forms a soluble solid white powder. Explain the properties of this gold salt using the ionic lattice model.
b) Gold (I) salt forms a solid where gold ions and other ions are lightly held together in a lattice. When it dissolves charged particles can move and conduct electricity and heat, the ions seperate and mix with the water, forming a white powder. The strong bonds in the ionic lattice explain why the salt has a high melting point and can dissolve in water.
LOOK ON NOTES FOR THE VSEPR shape table
Separation techniques: solubility depends on solar character
Polar solute+ Polar solvent= soluble
(Strong attraction)
Polar solute+ Non polar solvent= Insoluble
(Strong attraction)
Non polar solute+ Polar solvent= insoluble
(Strong attraction)
Non polar solute+ non polar solvent =soluble
(Weak attraction)
