Bonding, structure, and the properties of matter Flashcards
What are ions?
Charged particles , single atoms or groups of atoms
Why do atoms lose or gain electrons to form ions?
To get a full outer shell
What happenes when metals form ions?
they lose electrons from their outer shell to form positive ions
what happenes when non-metals form ions?
they gain electrons into their outershell to form negative ions.
What are the three types of bonding?
ionic, covalent and metalic
What happens when a metal and non metal react together?
The metal atom loses electrons to form a positively charged ion and the non-metal gains these electrons to form a negatively charged ion.These oppositely charged ions are strongly attracted to one another by electostatic forces (ionic bond)
What is a Dot and Cross diagram?
It shows the arrangement of electrons in an atom or ion.Each ion represented by a cross or dot, to show which atom the electrons orginally came from.
What structure do ionic compounds have?
A closely packed regular lattice arrangement and there are very strong electrostatic forces of attraction between oppositely charged ions, in all directions in the lattice. ( Giant ionic lattice)
Properties of Ionic compounds
High melting points and high boiling points.
When solid,the ions are held in place so can’t conduct electricity.
When melted, ions are free to move so they’ll carry electric current.
Some ionic compounds also dissolve in water.
How to work out empirical forumla?
Work out what charges the ions will form, then balance them out.
What is covalent bonding?
When non-metal atoms bond together, they share pairs of electrons
What does each single covalent bond provide?
One extra shared electron for each atom
What are simple molecular substances?
molecules containing a few atoms joined together by covalent bonds
Properties of simple molecular substances
held together by very strong covalent bonds.By contrast, the forces of attraction between these molecules are very weak.
To melt or boil it you just need to break the feeble intermolecular forces and not the covalent bond.So the melting and boiling points are very low because they are easily parted.
Gases or liquid at room temperature(most)
bigger molecules= stronger intermolecular forces
How to draw polymers
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What is a polymer?
lots of small units linked together to form a long molecule that has repeating sections, all the atoms are joined by strong covalent bonds.
What is a giant covalent structure?
all the atoms are bonded together by strong covalent bonds .
Examples of Giant covalent structures
Diamond , graphite and silicon dioxide
What are allotropes?
Allotropes are different structural forms of the same element in the same physical state.
About a diamond
Made up of carbon atoms that each form four covalent bonds.Makes diamond really hard.
strong covalent bonds take a lot of energy to break and give diamond a very high melting point.
doesn’t conduct electricity because it has no free electrons.
About Graphite
each carbon atoms forms three covalent bonds creating sheets of carbon atoms arranged in hexagons.
soft and slippery because no covalent bonds between the layers
High melting point, delocalised electrons so can conduct electricity and thermal energy
What is graphene?
a sheet of carbon atoms joined together in hexagons.Incredibly light , contains delocalised electrons so can conduct electricity.
What are fullerenes?
molecules of carbon shaped like closed tubes or hollow balls.
Mainly made up of carbon atoms arranged in hexagons, sometimes in pentagons or heptagons
conducts electricity and thermal energy
high tensile strength
can form nanotubes - tiny carbon cylinders
What is metallic bonding?
When a metal reacts with a metal.
outershell electrons are delocalised.Strong forces of electrostatic attraction between the positive metal ions and the shared negative electrons.
