Unit 1 Flashcards
What is a covalent bond?
The common attraction of two nuclei for a shared pair of electrons
What is the covalent radius?
The measure of the size of an atom from the middle of the atom to the middle of a covalent bond
What is electronegativity?
The attraction an atom has for the electrons in a bond
What is ionisation energy?
The energy required to remove one mole of electrons from one mole of gaseous atoms
What are the first 3 ionisation energies
E(g) —> E+(g) + e-
E+(g) —> E2+(g) + e-
E2+(g) —> E3+(g) + e-
What happens to the covalent radius when you move down a group?
It increases due to more energy levels (nucleus is further away from bonding electrons) and more shielding (outer electrons are blocked from nucleus by inner electrons)
What happens to the covalent radius moving across the period
It decreases
What happens to the electronegativity when you move across the period
It increases due to greater nuclear charge or more protons
What happens to the electronegativity moving down a group
It decreases due to shielding and more energy levels
What happens to the trend in the first ionisation energy going across a period
It increases due to greater nuclear charge or more protons
What happens to the trend in the first ionisation energy when you go down a group
It decreases due to more shielding and more shells (outer electrons are further away from nucleus)
What bond cant elements have?
Ionic, and they cant be polar
What are weak bonds
Weak bonds do not exist
What is oxidation
Loss of electrons
What is reduction
Gain of electrons
What do reducing agents do
They donate electrons
What do oxidising agents do
They accept elections
What is the e-neg value in reducing agents
They have a low e-neg value
What is the e-neg value in oxidising agents
They have a high e-neg
What group are reducing agents
Group 1
What group are oxidising agents
Group 7
Can reduction/oxidation reactions happen on their own
No, they occur together in redox reactions
What are the diatomic elements
H2, N2, O2, F2, Cl2, I2, Br2
What are the polyatomic elements
P4, S8, fullerenes (C60)
