Metallic Bonds

Which has more resistance, a 100W lightbulb or a 60W one?

A 60W one because there is less power, so there must be more resistance

Define superconductor

A material that conducts electricity with no resistance

When do some metals display superconductivity?

At extremely low temperatures that are near absolute zero

How do we classify a bond between two atoms?

Based on the bond type that manifests itself the most

Why is this (Typically, the [blank] the number of delocalized electrons in the conduction band, the better the thermal and electrical conductivity) ?

Because fewer delocalized electrons give the metal cations more freedom of vibration, so they can pass on KE easier Additionally, this would mean that there is less traffic and thus easier for the movement of electrons

Why do most metals have high melting and boiling points?

Because of the strength of the metallic bond

Why does conductivity increase as you go down a group?

Because the bond strength decreases, which increases the freedom of motion

Why does conductivity decrease as you go across a period?

Because the bond strength increases, which reduces the freedom of motion

Why is this (The greater a metal's temperature, the [blank] the resistance.) ?

Because the cations vibrate more rapidly, which makes it harder for the delocalized electrons to move on the conduction band

Why is the previous true (The strength of the metallic bond and the hardness of the metal is directly proportional to [blank].) ?

Because the delocalized electrons act as the glue that cements the metal ions in place, so the greater number, the stronger the cement

Why is this (Metals tend to be [blank] conductors of electricity.) ?

Because the delocalized electrons are free to move from one metal atom to the next along the conduction bands

Why do we say that the metal atom is a positively charged metal ion once an electron is in the conduction band?

Because the electrons have "left" the metal atom, in the sense that they are no longer restricted to that particular atom

Why are the electrons able to easily jump to higher energy levels?

Because the energy difference between the outermost energy level and these higher energy levels is nominal

As you go down a group, why does the malleability increase?

Because the hold on the electrons gets worse

Why is this (What kind of structure does a metal have?)?

Because the many energy levels that make up the conduction band are close together, so the delocalized electrons are able to absorb and re-emit most wavelengths within the visible spectrum Because the crystalline structure of a solid makes the surface very regular, photons not absorbed are reflected at a distinct angle, which makes it appear silver and reflective

Why does the metallic bond weaken as the hold on the electrons decreases?

Because the positive metal ions are not as strongly attracted to the delocalized electrons As a result, the metal ions are not cemented as securely and therefore, bound less strongly

Why are delocalized electrons called that?

Because they are capable of moving from one positive metal ion to another and another within the metal (they are not restricted to just a single pair of atoms involved)

Why do Group I metals tend to be soft?

Because they only donate one electron

Why are the copper and zinc families not hard?

Because they send the fewest d electrons of the transition metals, due to them having filled d's

Metallic bonds are held together how?

By a mutual attraction to the delocalized electrons that surround the positive metal ions

What does resistance do?

Causes electrical energy to be lost in the form of heat

Scientists have developed new materials that are superconductive at much higher temperatures that a similar to what?

Ceramic materials

What kind of structure does a metal have?

Crystalline (when solid)

What will decreasing a metal's temperature do to the electrical conductivity?

It will increase it because it slows down the vibrating metal ions, which decreases resistance

What are some things these new superconductors could be used for?

Magneto-lift trains, more powerful computer chips, and more powerful particle colliders

What happens once an electron is in the conduction band?

Said electron is free to move from one metal atom to the next (bc master has given the electron a sock)

Metals are typically what color?

Silver (except gold and copper)

[Blank] metals tend to be more malleable and ductile.

Softer

High melting/boiling point exceptions like mercury suggests what?

That covalent bonding somewhat plays a part

What does possessing fewer delocalized electrons in the conduction band indicate?

That the metal ions are not as firmly locked into position

Why are metals good conductors?

The bond allows the metal cations enough freedom of movement that they can pass KE on through vibration, and the delocalized electrons can transfer KE through cation collisions or collisions with other delocalized electrons

Define forbidden zone

The energy gap in the metal atoms that the electrons must jump

Define resistance

The friction-like force that opposes the flow of electrons within a conductor

Where do the delocalized electrons come from?

The positive metal ion's valence electrons, and in some cases, some electrons from the d sublevel in the second highest energy level

Define conduction band

The set of higher energy levels to which the valence and d electrons jump

What are some downfalls of these new superconductors?

Their brittleness, the fact that they can't be made into wires, and their habit to lose their superconductivity over time

Why are metals arranged in an orderly fashion?

To minimize repulsion and maximize attraction in an effort to make the metal more stable

Why do metals tend to be fairly malleable and ductile?

When a mechanical force is applied to a metal, the positive ions can simply slide over one another because the delocalized electrons help to offset repulsion between the cations well enough so that the cations can slip into a new stable arrangement

Is there ever a time when resistance is desirable?

Yes, in the case of incandescent lightbulbs or toasters

The more delocalized electrons donated, the [blank] the strength of the bond.

better

A metallic bond's electrons are [blank].

communally shared

Typically, the [blank] the number of delocalized electrons in the conduction band, the better the thermal and electrical conductivity

fewer

Metals are typically [blank] conductors of heat.

good

Metals tend to be [blank] conductors of electricity.

good

The greater a metal's temperature, the [blank] the resistance.

greater

The weaker the metallic bond, the [blank] the metallic nature.

greater

Metals tend to have [blank] densities.

high

The conduction bands of metal atoms are [blank].

intertwined

The force of attraction in a metallic bond is [blank].

omnidirectional

Reactivity and metallic nature are [blank].

synonymous

The strength of the metallic bond and the hardness of the metal is directly proportional to [blank].

the number of delocalized electron contributed by each atom