KS5 Unit 1 example Flashcards
Define dative covalent bond
A covalent bond in which both of the electrons in the bond are donated from one atom.
Define electronegativity
The power of an atom to attract the electron pair in a covalent bond
Define first ionisation energy
The energy required to remove 1 mole of electrons from a mole of isolated gaseous atoms to form 1 mole of +1 ions under standard conditions.
Define isomer
One of two (or more) compounds with the same molecular formula but different structural formula (or arrangement)
Explain the trend in ionisation energy down a group
Decrease - Greater distance between outer electron and nucleus, greater shielding, therefore less electrostatic attraction
What is the type of bonding in diamonds
giant macromolecular covalent lattice. Each carbon atom bonded to 4 others
Explain why aluminium has a higher melting point than Lithium
Al forms 3+ ions and each ion donates 3 electrons. Therefore greater charge density and electrostatic attraction between ions and delocalised electrons
Why can metals conduct electricity
Delocalised electrons are able to flow in a direction
What is the relative mass of an electron
1/1840
Why are metals malleable
Metal ions are able to slide past on another
What is buckminsterfullerene
Allotrope of Carbon. Forms giant macromolecular spheres with formula C60
Define allotrope
Pure elements that can exist in different physical forms in which their atoms are arranged differently. For example diamond and graphite are allotropes of carbon
Why are elements placed within the p-block of the Periodic Table
Outer electron is found within a p-orbital
How many electrons can be fit into the 1st-2nd-3rd-4th electron shells
2-8-18-32
What is required for a hydrogen bond to form
1 - A very electronegative atom covalently bonded to a hydrogen.
2 - A lone pair of electrons on another very electronegative atom (O,N,F)
