S5 - Unit 1 Flashcards
What happens in an oxidation reaction?
Electrons are lost
What happens in a reduction reaction?
Electrons are gained
What happens in an oxidation reaction apart from losing electrons?
Either hydrogen is lost or oxygen is added
What are the steps involved in writing the equation for a reduction reaction in an acidic solution?
- Balance the main element thats not oxygen
- Balance the oxygen by adding water
- Balance the hydrogen by adding hydrogen ions
- Balance the charge by adding electrons
What are titrations used for?
Measuring the concentration if a solution
What is atomic size?
The covalent atomic radius which is half the distance between the nuclei of two bonded atoms in an element
What happens to atomic size across a period and why?
Decreases due to increasing nuclear charge (protons)
What happens to the atomic size down a group?
Increases due to to increases no. of shells causing a shielding effect
What is electronegativity?
A measure of the tendency of an atom to attract a bonding pair of electrons
What happens to the electronegativity across a period and why?
Increases due to the nuclear charge increasing
What happens to the electronegativity down a group and why?
Decreases due to the increasing atomic size caused by extra shells, causing a shielding effect
What is ionisation energy?
The energy required to remove one mole of electrons from one mole of gaseous atoms
What happens to the ionisation energy across a period?
Increases due to increasing nuclear charge
What happens to ionisation energy down a group?
Decreases due to the shielding effect
What is the second ionisation energy definition?
The energy required to remove one mole of electrons from one mole of positive gaseous ions