Structure 1.3 Flashcards
What happens when electrons gain energy?
They become excited and move to higher energy shells. However, they can’t hold on the energy and emit it as photons of light and fall back to the lower energy shells.
Why does it require more energy to remove second and successive electrons from an ion?
As number of protons exceeds number of electrons so electrostatic attraction pulls electrons towards the nucleus
Why would first ionisation energy be higher?
Full outer shell, close distance between protons in nucleus and electrons
First ionisation energy
Energy required to remove one electron from an atom in the gaseous state (kj mol-1)
Each element produces an emission spectrum - what is this?
Discrete lines at particular wavelengths corresponding to the differences between energy levels.
What is the exception to aufbau principle?
Chromium and copper - 3d is filled before 4s
Pauli’s exclusion principle
No two electrons can have the same four quantum numbers - in practise, each orbital can only contain a max of two electrons
Hund’s rule
If two or more orbitals of equal energy are avaliable, electrons will occupy them singly before filling them in pairs
Movement of electrons between shells is called what?
Electron transititions
How can you tell the relative energy of a shell?
Energy emitted from electron transititions can be detected and wavelength measured
What electron transitions produce UV light?
n=7/6/5/4/3/2/ to n=1
What is (n)
Principal quantum number
Which electron transmitions produce infrared light
n=7/6/5/4 to n=3/4/5/6
Which electron transitions produce visible light?
n=7/6/5/4/3/ to n=2
Each atomic orbital can hold how many electrons?
Two electrons spinning in opposite directions
Aufbau principle
Electrons will fill the lowest avaliable energy level before filling higher levels
Orbital diagram
Represents how electrons are arranged in atomic orbitals, called electron configuration
Atomic orbital
A volume in space where there is a high probability that electrons are located
Each atomic orbital can hold how many electrons?
Two electrons spinning in opposite directions
The movement of electrons between shells is called what?
Electron transitions
Each element produces an emission spectrum - what is this?
Discrete lines at particular wavelengths correspond to the differences between energy levels.
Which electron transitions produce infrared light?
n>3 to n=3
What is (n)
Principal quantum number
Which electron transitions produce visible light?
n>2 to n=2
Which electron transitions produce UV light?
n>1 to n=1
How can you tell the relative energy of a shell?
The energy emitted from electron transitions can be detected and wavelength measured
