Bonding, Structure and Properties of metals Flashcards
What are ions?
They are charged particles which can be single atoms ( CL-) or groups of atoms (N0 3-)
When atoms lose or gain electrons what are they trying to achieve?
They are trying to achieve a full outer shell like a noble gas as atoms with full other shells are very stable.
How do metals form ions?
They lose electrons into their outer shell to form positive.
How do non-metals form ions?
They gain electrons into their outer shell to form negative ions.
The number of electrons lost or gained is the same as what?
It is the same as the charge on the ion. e.g. if 2 electrons are lost the charge is 2+
What groups on the periodic table are likely to form ions?
Group 1 and 2 and 6 and 7
What ions do Group 1 and 2 metals form?
they lose electrons to form positive ions.
What ions do Group 6 and 7 non-metals form?
they gain electrons to form negative ions.
What is a chemical bond?
it is an electrostatic attraction between a positive and a negative ion.
What is Ionic bonding?
It is an electrostatic attraction between oppositely charged ions. (when a metal and a non-metal react)
What happens when Lithium reacts with fluorine?
The lithium loses its outer electron and the fluorine atom gains it, now both the lithium atom and fluorine atom have a full outer energy level with ions.
Describe what happens when Sodium reacts with Chlorine (4 marks)
One electron passes from the sodium atom to the chlorine atom, both atoms achieve a full outer energy level.
How does a sodium atom turn into a sodium ion?
It loses one electron and gains a charge of 1+
Explain why the chloride ion has a negative charge.
one more electron than protons
Chloride ions are strongly attracted to sodium ions in sodium chloride. Explain why.
Because oppositely charged ions attract each other
All group 7 elements can produce ions.
What is the charge on the ions produced by group 7 elements?
-1
Many ionic compounds from what ?
Crystals
What type of structures do ionic compounds form?
They form giant structures called giant ionic lattice where every positive ion is surrounded by negative ions.
What do Giant ionic lattices have?
Very strong forces of attraction between positive and negative ions, which is called electrostatic forces.
What do the electrostatic forces do in giant ionic lattices?
They hold the positive and negative ions in place.
What are electrostatic bonds called in a giant ionic lattice?
Ionic bonds, attracting in all directions.
Are giant ionic lattices 2D or 3D?
3D
Give 2 properties of Ionic Compounds?
1) Ionic compounds have very high melting and boiling points.
2) Ionic compounds cannot conduct electricity when they are solids.
3) Ionic compounds can conduct electricity wen they are melted or dissolved in water.
Why do ionic compounds have very high melting and boiling points?
Because the strong electrostatic forces require a great deal of heat energy to break the forces.
Why can Ionic compounds not conduct electricity?
Because the ions cannot move. They are locked in place by the strong electrostatic forces of attraction.
Why can ionic compounds conduct electricity when melted or dissolved in water?
Because the ions can now move and carry the charge.
Explain why the ions in this lattice stay in place
Sodium ions have a (single) positive charge and chloride ions have a (single) negative charge.
Ions with opposite charge are attracted (to each other) .
(Positive and negative) ions are arranged alternatively (in each direction)
On a dot and cross diagram metals are drawn with what?
Cross
On a dot and cross diagram non- metals are drawn with what?
Dots
What is covalent bonding?
When non-metal atoms bond together which share pairs of electrons
What does H2 tell us?
There are two hydrogen atoms bonded together
What happens when two hydrogen atoms react together?
Now both hydrogen atoms have 2 electrons meaning they have a full outer energy level, just like a group 0 noble gas. By sharing a pair of electrons the atoms have formed a single covalent bond.
What does a energy levels diagram show?
shows the energy levels and the covalent bond.
What is a dot and cross diagram?
it only shows electrons not the energy levels
What does a stick diagram show?
it shows what type covalent bond it is (shared paired of electrons)
What is the stick diagram for oxygen?
0=0
What is the stick diagram for Nitrogen?
N (triple bond)N
Covalent bonds are usually what?
simple small structures
What are the two properties of covalent bonds?
They have low melting and boiling points
2) Small covalent molecules do not conduct electricity
Because small covalent molecules have low melting and boiling points what does it mean its state is at room temperature?
Gases or liquids at room temperature, this is because they all boil at temperatures below room temperature.
Explain why small covalent molecules have low melting and boiling points?
The weak intermolecular(between molecules) forces between the molecules do not require a lot of energy to break.
Covalent bonds have what between atoms?
They have strong covalent bonds between atoms
Using hydrogen as an example, explain why small covalent molecules have low melting and boiling points?
Hydrogen molecules in liquid forms is at very cold temperatures, as we increase the temperature the vibration of molecules increase, at a certain point, this vibration is Strong enough to break the weak intermolecular forces, holding the molecules to each other, at this point the molecules turns into a gas (boil).
What are alkanes?
Small covalent molecules
Why do alkanes boiling point increase as they get larger?
The intermolecular forces increase which requires more energy to break.
Why don’t small covalent molecules conduct electricity?
This is because the molecules do not have an overall electrical charge.
One of the gases present in the atmosphere is water vapor. Describe the bonding in this compound. (You must include electronic structures in your explanation.)
[4 marks]
Outer electronic structure of oxygen - has 6 electrons in outer shell. Outer electronic structure of hydrogen - has one electron two shared pairs of electrons (as covalent bond) outer electronic structure of compound correct or each atom now has a full outer shell/noble gas electron structure.