Unit 1 - Subtopic B Periodicty Flashcards
how are elements on the periodic table arranged
by increasing atomic number
Going down a group in the periodic table
the elements contaon the same number of outer electrons but add an extra outer shell each time
Going along a period on the periodic table
elements move from metallic to non-metallic and add an outer electron each time
Metallic Elements (first 20 elements)
Lithium
Beryllium
Sodium
Magnesium,
Aluminium
Potassium
Calcium
Covalent Molecular elements
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Phosphorus
Sulphur
Covalent network (first 20 elements)
Boron
Carbon (diamond and graphite)
Silicon
Monatomic
Noble gases
What is the covalent radius
a measure of the size of an atom
What happens to the covalent radius as you go across a period
the covalent radius decreases as the nuclear charge increases (higher nuclear charge pulls the outer electrons in closer)
What happens to the covalent radius as you go down a group
the covalent radius increases as the number of occupied shells increases (more shells = bigger atom)
What is the first ionisation energy
The energy required to remove one mole of electrons from one mole of gaseous atoms
What is the second ionisation energy
the energy required to remove the 2nd mole of electrons
What generally happens to ionisation energy as you go across a period
increase as a nuclear charge increases
What generally happens to ionisation energy as you go down a group
devreases as there are more shells, which means there is an increased screening effect due to the inner electrons.
What is the electronegativity
a measure of the attraction which an atom (involved in a bond) has for the electrons in the bond
