A1 - atomic structure, bonding and shapes and molecules Flashcards
Definition of isotope
Atoms of the same element with different number of neutrons and different masses
Definition of isoelectronic
Atoms with the same number of electrons
Definition of relative atomic mass
The weighted mean mass of an atom of the element compared with 1/12th mass of carbon - 12
Definition of relative isotopic mass
The mass of an isotope compared with 1/12th mass of an atom of carbon 12
How many orbitals are in an s-subshell
1 - holds two electrons
What is the order of electronic configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d10
What is an orbital
A region of space where an orbital usually is
Hunds rule about electron configuration
Electrons prefer to occupy orbitals on their own and only pair up when no empty orbitals have f the same energy are available
What is the Aufbau principle about electron configuration
Electrons are placed into shells starting with the lowest energy level first - each shell must me full before the next shell starts to fill
How many subshells in the first shell
1
How many electrons can an s-orbital hold
2 electrons
How many electrons can a p orbital hold
6
How many electrons can d-orbitals hold
10
What orbitals are in the first sub shell
S
What orbitals are in the second subshell
S and P
What orbitals are in the 3rd subshell
S p d
What is the maximum number of electrons in the first shell
2
What is the maximum number of electron in the 2nd shell
8
What is the maximum number of electrons in the 3rd shell
18
Why are 4s subshells filled before 3d subshells
4s subshells had lower energy than the 3D subshell
Definition of ionic bonds
The electrostatic attraction between oppositely charged ions in all directions
What two factors determine the strength of ionic bonding
Magnitude of charge
Size of ion
Why does a smaller ion have a stronger ionic bond
More compact electrostatic density so stronger attraction between ions
Why does having a larger charge on the ion mean a greater ionic bond
Increased pull from the protons in the neutron has a stronger effect on the electrons drawing them closer and having a stronger attraction between ions
What is the definition of a covalent bond
The electrostatic attraction between a shared pair of electrons and a nuclei
Definition of a dative covalent bond
Where a shared pair of electrons has come from a single atom
What is a sigma bond
Bond formed by direct overlap of orbitals
What is a pi bond
Forms by sideways overlap of p orbitals
What shape and bond angle is a molecule with 2 bonded pairs
Linear - 180
What shape and bond angle is a molecule with three bonded pairs
Trigonal planar
120
What shape and bond angle is a molecule with 4 bonded pairs
Tetrahedral - 109.5
What shape and bond angle is a molecule with 5 bonded pairs
Trigonal bipyramidal
120,90
What shape and bond angle is a molecule with 6 bonded pairs
Octahedral - 90
Why do bond angles decrease by 2.5 degrees when there are lone pairs
Because lone pairs repel stronger than bonded pairs
What is the shape and bond angle of a molecule with 3 bonded pairs and 1 lone pair
Pyramidal - 107
What is the shape and bond angle of a molecule with 2bonded pairs and 2 lone pairs
Bent v shape
104.5
109.5-2.5-2.5
Definition of relative molecular mass
Average mass of a molecule compared to 1/12tb the mass of a carbon atom
Definition of Relative atomic mass
The average mass of one atom compared to 1/12th the mass of one atom of carbon
Electronic configuration of
Cr
1s2 2s2 2p6 3s2 3p6 4s1 3p5
Cu electronic configuration
1s2 2s2 2p6 3s2 3p6 4s1 3d10
Why can ice float on water
Solid water forms an open lactice where the water particles are spaced further apart making the ice less dense
