Bonding Flashcards
(35 cards)
What elements form a ionic bond
Metal and non-metal
What happens is ionic bonding
-the metal loses electrons to form a positively charged ion
-the non-metals gain these electrons to form a negatively charged ion
-these oppositely charged ions are strongly attracted due to electrostatic forces
What are positive ions called
Cations
What are negative ions called
Anions
What elements form a covalent bond
Non-metals
What structure do ionic compounds have
-A giant ionic lattice
-the ions have strings electrostatic forces of attraction in all directions in the lattice
Properties of ionic compounds
-high … and boiling …
->a lot of … is needed to … the … of attraction
-when … can’t … electricity
-when … can conduct … because the … are … to move so can … electric …
-some … in …
-high melting and boiling points
->a lot of energy is needed to overcome the forces of attraction
-when solid can’t conduct electricity
-when liquid can conduct electricity because the ions are free to move so can carry electric charge
-some dissolve in water
What happens in covalent bonding
-atoms only share electrons in their outer shells (highest energy levels)
-each covalent bond provides an extra shared electron for each atom
-there are enough covalent bonds to fill up the outer shell making it stable
What are the different ways of drawing bonds
-dot and cross diagram, uses o ans x
-displayed formulas, where u write the symbol and draw straight lines between them eg Cl-Cl
Properties of covalent bonds
-have very strong … forces of … with the … in a molecule
-weak … forces of … between the …
-… melting and … point
-mainly … or gases at … temp
-as the … gets … the intermolecular … become …
-… conduct … as there are no free …
-have very strong electrostatic forces of attraction with the atoms in a molecule
-weak intermolecular forces of attraction between the molecules
-low melting and boiling points
-mainly liquids or gases at room temp
-as the molecule gets bigger the intermolecular forces become stronger
-don’t conduct electricity as there are no free electrons
What are giant covalent structures
Macromolecules
What happens in giant covalent structures
All the atoms are bonded to eachother by string covalent bonds
Properties of giant covalent structures
-very high melting and boiling points
-don’t conduct electricity
Examples of giant covalent structures
-diamond
-graphite
-silicon dioxide
Structure of diamond, graphite and silicon dioxide
Diamond:
-each … atom forms … covalent … in a … structure
Graphite:
-each carbon atom forms … covalent … to create layers of …, each … atom has 1 … electron
Silicon dioxide:
-made of … and oxygen
Diamond:
-each carbon in atom forms 4 covalent bonds in a rigid structure
Graphite:
-each carbon atom forms 3 covalent bonds to create layers of hexagons, each carbon atom has 1 delocalised electron
Silicon dioxide:
-made of silicon and oxygen
Why is diamond very hard
-is a giant covalent structure
-made up of carbon atoms that each form 4 covalent bonds
-this makes diamond very hard
Why does diamond have a very high melting point
-it’s a giant covalent structure
-made up of carbon atoms that each form 4 covalent bonds
-the covalent bonds take a lot of energy to overcome
Why does diamond not conduct electricity
-as each carbon atom forms 4 covalent bonds
-it has no free electrons or ions
-so no electricity can be transported throughout the material
Why is graphite soft, slippery and a good lubricant
-each carbon atom forms only 3 covalent bonds
-there are no covalent bonds between layers
-so they are free to move over eachother
Why does graphite have a high melting point
-the covalent bonds in the layers require a lot of energy to overcome
Why can graphite conduct electricity
-only three out of carbons 4 outer shell electrons are in a covalent bond
-each carbon atom as one delocalised electron
-these electrons can carry electrify through the layers
What is graphene
-… layer of …
-it is … atom … and is two-…
-it is very …
-has … covalent …
-can conduct …
-one layer of graphite
-it is one atom thick and is two-dimensional
-it is very light
-has strong covalent bonds
-can conduct electricity
What are fullerenes
-molecules of … shaped like closed … or … balls
-they are mainly made up of … atoms arranged in …, pentagons or h…
-molecules of carbon shaped like closed tubes or hollow balls
-they are mainly made up of carbon atoms arranged in hexagons, pentagons or heptagons
What atoms are fullerenes made of
Carbon atoms
