Karteikarten
Chemistry keyword definitions F321
Karten in diesem Stapel (41)
- 1IsotopeAtoms of the same element, with the same number of protons but a different number of neutrons
- 2Relative atomic massThe average mass of the naturally occurring isotopes of the element relative the mass of an atom of carbon-12, which has a mass of 12
- 3Relative isotopic massThe average mass of a naturally occurring isotope of the element relative to the mass of an atom of carbon-12, which has a mass of 12
- 4Avogadro's ConstantThe number of particles per mole (6.02*10^23 mol^-1)
- 5MoleThe mole is defined as the amount of substance which contains as many elementary particles as there are atoms in 12g of carbon-12
- 6Molar massThe molar mass is the mass (in g) of one mole of substance. It has units of gmol-1
- 7Empirical formulaThe simplest whole number ratio of atoms of each element present in a compound
- 8Molecular formulaThe actual number of atoms of each element in a molecule
- 9ConcentrationThe amount of solute (in mol) per 1dm^3 of solution, has the units moles per dm^3 (mol dm^-3).
- 10AcidsProton donors. When they’re in water they release H+ ions into the solution.
- 11BasesProton acceptors, they take H+ ions and neutralise acids.
- 12AlkaliSoluble base which releases OH- ions in solution.
- 13SaltProduced when a H+ ion is replaced by a metal ion or NH4 +.
- 14AnhydrousSubstance containing no water molecules.
- 15HydratedCrystalline compound containing water molecules.
- 16Water of CrystallisationWater molecules which form part of the crystalline structure of a (hydrated) compound.
- 17OxidationLoss of electrons (OIL, oxidation is loss), increase in oxidation number shows that a species has been oxidised.
- 18ReductionGain of electrons (RIG, reduction is gain), decrease in oxidation number shows that a species has been reduced.
- 19Redox reactionA reaction in which species are both reduced and oxidised.
- 20Disproportionation reactionA reaction in which the same species is both reduced and oxidised.
- 21First Ionisation energyThe energy required to remove one electron from each atom in one mole of gaseous atoms to make one mole of gaseous unipositive ions
- 22Second Ionisation energyThe energy required to remove one electron from each unipositive ion in one mole of gaseous unipositive ions to make one mole of gaseous dipositive ions
- 23Nuclear chargeThe attraction from the protons in the nucleus with electrons. Protons have a positive charge and electrons have a negative charge, the greater the number of protons (The atomic number of the element), the greater the nuclear charge. Increases along a period. A higher nuclear charge makes it more difficult to remove an electron from the atom’s outer shell, causing the ionisation energy to increase.
- 24Electron shieldingThe number of shells of electrons between the nucleus and the outer shell of electrons. Increases down a group. Electrons repel each other so the more electrons repelling the electrons in the outer shell, the easier it’ll be to remove them, causing the ionisation energy to decrease.
- 25Atomic radiusThe distance from the outer shell of electrons to the nucleus of the atom. Increases down a group. A greater atomic radius means the outer shell electrons are under less influence from the attraction from the nucleus, this makes it easier to remove the electrons, causing the ionisation energy to decrease.
- 26OrbitalA region that can hold up to two electrons of opposite spins (Up and down). Orbitals in an s-subshell are spherical, orbitals in a p-subshell are hourglass shaped.
- 27SubshellThe space an electron can occupy within each shell. An s-subshell has one orbital (And so can hold a total of 2 electrons), a p-subshell has 3 orbitals (6 electrons), a d-subshell has 5 orbitals (10 electrons), and an f-subshell has 7 orbitals (14 electrons).
- 28Ionic bondingElectrostatic attraction between oppositely charged ions.
- 29Covalent bondingThe electrostatic attraction between a positively charged nucleus and a shared pair of electrons.
- 30Dative covalent bondingA bond formed when one of the bonding atoms gives both of a pair of electrons.
- 31Intermolecular forcesThe forces of attraction between molecules. The strength or amount of intermolecular forces are what affect the substance's melting/boiling points - Stronger intermolecular forces require more (heat) energy to break.
- 32ElectronegativityThe power of attraction between a bonded atom and a pair of electrons in a covalent bond.
- 33Dipole-dipole interactionsAn intermolecular force. Molecules with permanent dipoles allow for weak intermolecular bonds to be formed between the molecules.
- 34Van der Waal forcesVan der Waals forces are another type of intermolecular force. Van der Waals are formed when the movement of electrons unbalances the distribution of the charge in the shells, this causes an instantaneous dipole to form - This in turn attracts/repels electrons in neighbouring molecules which allows them to form instantaneous dipoles.
Van der Waals forces increase as the number of electrons in the molecules increases and as the surface contact of the molecules increases. - 35Hydrogen bondingThe interaction between the lone pair of electrons on a nitrogen, oxygen or fluorine atom and a hydrogen atom which is bonded to an N, O or F atom
- 36Metallic bondingThe attraction of positive metal ions to delocalised electrons.
- 37Giant ionic latticeFormed by the attraction of oppositely charged ions, each ion is surrounded by the oppositely charged ions and the ions attract each other to form a giant lattice.
- 38Giant covalent latticeThree dimensional structure of atoms bonded together by strong intramolecular covalent bonds.
- 39Giant metallic latticeLattices which contain ionised atoms in fixed positions with delocalised outer shell electrons which spread, and can freely move, throughout the structure.
- 40Simple molecular latticeThree dimensional structure of molecules bonded together by weak intermolecular forces, such as Van der Waals forces
- 41PeriodicityA repeating pattern of properties of elements across different periods in the Periodic table.
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- A Level Chemistry Karteikarten am Chemistry keyword definitions F321, erstellt von mollyt101 am 17/04/2015.
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