Unit 1 Flashcards
(34 cards)
What does elements in the same group have in common?
Similar chemical properties and same number of outer electrons
Why does covalent radius increase going across a period?
The numbers of protons are increasing which increases nuclear charge. The pull from nucleus gets stronger on outer electrons so electrons are pulled closer
Why does covalent radius decrease going down a group?
number of electrons shells increases in which the extra shells shield the outer electrons from pull of the nuclear charge
what is ionic radius?
The radius of an ion once the atom has lost/gained electrons
What happens to the ionic radius of metals when they become ions?
They lose an entire electron shell
What is the definition of first ionisation energy?
Energy required to remove one mole of electrons from one mole of atoms
Why does ionisation energy increase going across a period?
The number of protons is increasing, increasing nuclear charge, pull by nucleus gets stronger on the outer electrons so the electrons are pulled closer to the nucleus making it harder to remove them
Why does ionisation energy decrease going down a group?
number of electrons shells increases, extra electron shells shield outer electrons from the nuclear charge
What is the definition of electronegativity?
An atoms strength of it attraction to bonded electrons
Why does electronegativity increase going across a period?
number of protons is increasing, increasing nuclear charge, pull by nucleus gets stronger on outer electrons causing atom to become smaller
Why does electronegativity decrease going down a group?
Number of electron shells increases, atom size increases, extra electrons shells shield the outer electrons from nuclear charge pull
What is covalent bonding?
Mutual attraction of 2 positively charged nuclei for a shared pair of negatively charged electrons
What is ionic bonding?
Electrostatic attraction of positive metal ions and negative non-metal ions
What is metallic bonding?
Electrostatic attraction of positive metal ions and negative delocalised electrons
What elements does covalent molecular exist between?
Non metals and has low MP/BP
What elements does covalent network exist between?
Carbon, Boron, Silicon and has Very high MP/BP
What elements does Ionic Lattice exist between?
Metals+Non Metals and has Very high MP/BP
What elements does Metallic Lattice exist between?
Metals and has High MP/BP
What group is monatomic?
Group 8
What is phosphorus structure?
Covalent molecular (P4)
What is Sulphur’s structure?
Covalent molecular (S8)
What is a difference in 0.4 or below known as for electronegativity values in compounds?
Non-polar (Pure) covalent bonding
What is a difference in 0.4-2.2 known as for electronegativity values in compounds?
Polar covalent bonding
What is a difference in 2.3 or above known as for electronegativity values in compounds?
Ionic bonding
