AS 1 - Definitions Flashcards
What is an ion?
Atoms which have lost/gained electrons.
They have charge.
What makes up an atom?
Protons, neutrons and electrons
Relative Atomic Mass
Average mass of an atom of an element relative to one twelfth of carbon-12
Isotopes
Atoms which contain same number of protons but a different number of neutrons
Relative Isotopic Mass
The mass of an atom of an isotope of an element relative to one twelfth of carbon-12
Relative Molecular Mass
Average mass of a molecule relative to one twelfth of carbon-12
Avogadro’s number
Number of atoms in 12g of Carbon-12
Molar Mass
Mass of one mole of a substance
Empirical Formula
Simplest whole number ratio of atoms of each element in a compound
Water of crystallisation
Water that is chemically bonded within a crystal structure
What are the steps in mass spectrometry?
Ionisation > Acceleration > Deflection > Detection
Molecular Ion
Ion formed by removal of an electron from a molecule
Ground state
An electron configuration in which all the electrons are in the lowest available energy levels
How does nuclear charge effect ionisation?
Higher charge - higher attraction
How does atomic radius affect ionisation?
Smaller radius > greater attraction
How does electron shielding affect ionisation?
Inner shells repel outward > reducing attraction of outer shells
Octet rule
When forming compounds, an atom tends to gain, lose or share electrons to achieve eight electrons in its valence shell
Coordinate bond
A shared pair of electrons between two atoms where one atom provides both
Bonding pair
A pair of electrons shared between two atoms
Lone pair
A pair of unshared electrons in the outer shell of an atom
Polar bond
A covalent bond in which there is unequal sharing of the bonding electrons
Electronegativity
The extent to which an atom attracts the bonding electrons in a covalent bond
Delocalised electrons
Outer electrons that do not have fixed positions but move freely
What leads to induced dipoles and Van der Waal forces?
Asymmetry in the electron cloud which produces the dipoles
Redox reaction
When oxidation and reduction occur in the same reaction
Oxidation
Loss of electrons
Loss of hydrogen
Gain of oxygen
Reduction
Gain of electrons
Gain of hydrogen
Loss of oxygen
Bond enthalpy
Energy required to break one mole of a specific bond
