Periodic table Flashcards
s block
Groups 1&2- outer electrons in the s orbital
P block
groups 3-0
Outer electrons in p orbital
D block
transition metals- outer electrons in d orbital
ionisation energy in the periodic table
General increase across a period. There is an increase in nuclear charge in the same energy level so there is little extra shielding and therefore a greater attraction between a nucleus and outer electrons
ionisation energy in Group 2 and 3
Decrease between Group Two and three. Group-Three elements the electron is in a new subshell of slightly higher energy level and is partially shielded by s-electrons
ionisation energy between Group Five and six
Decrease between five and six. In group six electron is removed from an orbital containing a pair of Electrons. The repulsion between these electrons makes an electron easier to remove. in group five the electron is removed from a singly occupied orbital
ionisation energy down a group
Decreases down a group. Her electron has increased shielding from inner electrons and is further from the nucleus. Outweighs the increase in the nuclear charge
Electronegativity across a period
bonding elecrons
Increases across a period. increase In nuclear charge but the bonding electrons are always shielded by the same inner electrons so there is a greater attraction between nucleus and bonding pair
Electronegativity down a group
bonding elecrons
Decreases down a group. Bonding electrons have increased yielding from the nucleus so the attraction between nucleus and bonding electrons decreases
Metals- melting and boilng temperatures
Have metallic bonding, there is an increase because the metallic bonding gets stronger. Ions have a greater charge and there is an increased number of delocalized electrons
Giant covalent structures eh. Silicon boron
Each atom is bonded covenantly to four other atoms and a large amount of energy is needed to break all these bonds
Simple molecular substances eh. P, S, Cl
Although the Covalent bonds between atoms in the molecules are strong the intermolecular forces holding the molecules together are weak and do not need much energy to break
Argon
Lowest melting boiling temperature because it exists as separate atoms held together by very weakened Induced dipole - induced dipole forces
Electron transfer- half equations
oxidation: Eg. Mgโ> Mg2+ + 2e
Reduction: Eg. Cu2+ + 2e โ> Cu
Group one metals with cold water
Form a hydroxide and hydrogen EG. Sodium
2Na + 2H2Oโ> 2NaOH + H2
Lithiumโs reaction with water
Floats on the water, gently fizzing
Sodiumโs reaction with water
Sodium melts into a bowl that dashes around the surface
Potassiumโs reaction with water
Potassium melts into a ball and catches fire
Cesiumโs reaction with water
caesium explodes and shatters the glass container