3 Electrons And The Periodic Table Flashcards
Bohr model
Theorised by Niels Bohr, he proposes that electrons revolve in fixed orbits around the nucleus, the electrons orbit correspond to specific energy levels in the atom, electrons can only occupy fixed energy levels and electrons orbits of larger radii correspond to energy levels of higher energy.
What are flame tests based on?
The ability of electrons to release absorb energy as they move from higher to lower energy levels.
What can flame tests detect?
The presence of a small number of metal elements
What is atomic absorption spectroscopy (AAS)?
The ability of electrons to absorb energy as been moved from lower to higher energy levels.
Can be used to detect a large range of elements, even in samples with low concentrations
What explain the origin of the emission spectra?
The Bohr model suggests that the atomic spectra of atoms is produced by electrons gaining energy from some source, jumping up to a higher energy level, then immediately dropping back to a lower energy level and emitting the energy difference between the two energy levels.
What is quantisation of energy?
the energy of the electrons only present at discreet levels
What is ground state?
The lowest or minimum energy state of an atom
Emission vs absorption Spectra
The range of colours of light absorbed by electrons, moving into higher energy levels
While emission is just the amount of like emitted
Each element has a unique absorption/emission spectrum
Define electrostatic attraction
The attractive force between opposite electric charges.
Strength depends on the magnitude of the charges involved and the distance between them
What is core charge?
The resultant attractive force experienced by valence electrons, wants the impact of the shielding affect provided by electrons in the inner shell is taken into account
Calculated by subtracting the total number of inner shell electrons from the number of protons in the nucleus.
What is atomic radius?
A measurement used to describe the size of an atom. It is the distance from the nucleus to the outermost electrons.
What are the property trends in the periodic table?
- Core charge increases across a period
- atomic radius, increases down a group, and decreases across a period
- ionisation energy and electronegativity decreases down a group, but increases across a period
What are successive ionisation energies?
The energy is required to remove multiple electrons, consecutively from an atom of an element in the gas phase
Define electronegativity
The ability of an element to attract electrons in a covalent bond towards itself
