C3 Flashcards
What do you call an ion with a positive charge
a cation
What do you call an ion with a negative charge
an anion
What is ionic bonding
The transfer of electrons from a metal to a non-metal involving forces of attraction between two oppositely charged ions
What is covalent bonding
Chemical bond where two non gases share pairs of electrons
What does a lattice structure mean
A regular repeated three-dimensional arrangement of atoms, ions, or molecules.
What is meant with a giant covalent structure
many atoms, each joined to adjacent atoms by covalent bonds.
What is allotrphe indicating
A different physical form of a element
What is an alloy
a mixture of metals, NOT a compound as the ratio of metals in the structure does vary. Alloys enhance the physical and sometimes chemical properties of pure metals.
What is a structure of an ionic compound
a lattice structure of one cation to an anion.
What makes solid sodium chloride different from other ionic compounds
Instead of staying in pairs after sodium and chloride turn into ions they cluster together so each ion is surrounded by 6 ions of a opposite charge
Properties of ionic compounds
Always solid at room temperature, high boiling and melting point, and the reason for that is their structure is a giant arrangements of ions held together by strong electrostatic attractions.
What can a high or low melting point tell you
If there’s a high melting point it means there’s lots of bonds and they’re also very strong.
What can a compound being soluble in water or oil tell you
Compounds that dissolve in water usually carry a charge, if they’re soluble in oil it means no charge
What can the electrical conductivity of the ionic compound when solid and in solution tell us about the mobility of the charged particles in these states?
If it’s a great conductor in solution it means the charged particle is quite mobile
Why are properties of products differ from the reactants
This is because the formation of the ionic bonds give them unique properties
Difference between ion and atom
ions are charged, atoms have no charge
What is a positive ion called
A cation
What is a negative ion called
an anion
What is covalent bonding
A chemical bond that involves the sharing of electron pairs between 2 non-metals
How is a covalent bond created
when a pair of electrons is shared between two atoms leading to noble gas electronic configurations
What are the diatonic molecules
Brinklehol
Br, I, N, Cl, H, O, F
What attractions are present in a covalent structure?
There’re strong force of attraction holding the atoms together, but weak intermolecular forces holding the structure.
Physical property differences in ionic and covalent compounds
Ionic compounds are usually soluble in water whereas covalent isn’t
Ionic compounds have higher boiling and melting points
Chemical differences of Ionic and covalent compounds
Bonding caused by electrostatic attraction for ionic, bonding caused by sharing of pairs of electrons for covalent
Usually conductive other than some outliers for ionic, usually unconductive other than graphite and diamond for covalent compounds
What are macromolecules
Substances with giant covalent structures such as diamonds and graphite
What are diamond and graphite
Allotropes of carbon that have high melting points and strong despite being non-metals.
Why is graphite like that
it has layers of carbon delocalised electrons moving freely and held by weak intermolecular foces.
Physical properties of metals
Malleable, ductile, lusturous, good conducts, dense, high tensile strength, high melting and boiling point
how does metallic bonding occur
- metal atoms are packed tightly
- cations of metal in sea of delocalised electrons
- causes strong electrostatic forces metallic holding the metal together
Why are some metals soft and others hard
It means it isn’t pure, The bonds in a metal are flexible because the bonding electrons are free to move. We say that the metallic bonds are non-directional. A metal with lots of perfect rows of ions will bend easily. If we “mess up” the rows (i.e. by adding larger ions or smaller atoms; making an alloy) they will not be able to slip easily and the metal will not bend easily.
What are alloys
mixtures of 2 elements one being a metal
Properties of alloys
Harder and stronger than metals thus more effective
Why are alloys stronger or harder
The difference sized ions make it harder for layers to slide over each other
What is an alloy made from alluminum and copper
Duralium and it’s lighter and stronger usually used in airplanes
