Question

Which of the following properties are better considered characteristic of the free isolated atoms, and which are characteristic of the bulk metal: (a) electrical conductivity, (b) first ionization energy, (c) atomic radius, (d) melting point, (e) heat of vaporization, (f) electron affinity?

Short answer

In summary, the properties characteristic of free isolated atoms are: (b) first ionization energy, (c) atomic radius, and (f) electron affinity; while the properties characteristic of bulk metals are: (a) electrical conductivity, (d) melting point, and (e) heat of vaporization.

Step-by-step solution

(a) Electrical conductivity

Electrical conductivity is a property related to bulk metals. It arises from the collective behavior of conduction electrons in a material and is not applicable to isolated atoms.

(b) First ionization energy

The first ionization energy is the energy required to remove an electron from an isolated atom to form a positive ion. As such, it is a property associated with isolated atoms.

(c) Atomic radius

The atomic radius is the measure of the size of an isolated atom. It is specifically related to the atom itself and does not depend on the interactions between atoms in bulk metals. Thus, it is characteristic of a free isolated atom.

(d) Melting point

The melting point of a substance indicates the temperature at which it transitions from a solid to a liquid state. Melting points are related to the interactions between atoms in a solid material and are, therefore, characteristic of bulk metals.

(e) Heat of vaporization

The heat of vaporization is the amount of energy needed to convert a given amount of a substance from the liquid phase into the vapor phase. As with melting points, the heat of vaporization depends on the interactions between atoms in a material, making it characteristic of bulk metals.

(f) Electron affinity

Electron affinity refers to the energy released when an electron is added to an isolated atom to form a negative ion. This property is directly related to the atom and does not depend on the interactions between atoms in bulk metals, making it a characteristic of the free isolated atoms. In summary: - Electrical conductivity, melting point, and heat of vaporization are properties characteristic of bulk metals. - First ionization energy, atomic radius, and electron affinity are properties characteristic of free isolated atoms.

Key concepts

Electrical Conductivity

Electrical conductivity is a fascinating property showcasing how well a material can carry an electric current. It's all about the flow of electrons, which act like tiny charged particles zipping through the material.

For metals, their sea of free-moving electrons allows them to conduct electricity really well, which is why they're used in wires and circuits. But if you were to look at a single isolated atom, you wouldn't find this property at all because conductivity depends on a bunch of atoms together where electrons can move freely from one to another.

First Ionization Energy

Imagine you have a tiny atom, and you want to take away one of its electrons - the amount of energy you'd need to use is called the first ionization energy.

This property is super individual to each atom. It tells us a lot about how tightly an atom's nucleus holds onto its outermost electron. Generally, the closer and more filled with electrons an atom's shell is, the more energy you'd need to strip an electron away. This is why it's a property of isolated atoms and not something you'd consider in a group of atoms or a metal.

Atomic Radius

Think of the atomic radius as the measure from the center of an atom's nucleus to the edge of its electron cloud. It's like the personal space bubble of an atom.

What's cool here is that every single atom has its own size and this doesn't really change whether it's playing solo or hanging out with others in a material. So, atomic radius is like a fingerprint for atoms, showing their size when they're just by themselves.

Melting Point

The melting point is all about team effort. It's the temperature where a solid becomes a liquid, and for that to happen, atoms in a material have to loosen up their bond with each other.

This means we're talking about a bunch of atoms together in a solid - a situation you won't find with just one atom flying solo. So while an isolated atom doesn't melt, the melting point is super crucial for understanding the behavior of a group of atoms in a bulk material.

Heat of Vaporization

The heat of vaporization is a bit like the energy needed for a big breakout - it's the horsepower required to turn a liquid into a gas. This energy breaks the muscly arms (bonds) holding atoms together in a liquid.

Just like with melting points, you need a team of atoms together to talk about vaporizing anything. It's a property of groups of atoms or molecules in a material, not something you'd ever use to describe a lone atom.

Electron Affinity

Now let's chat about electron affinity, the love an atom has for an extra electron. This is measured by the energy released when an atom in the free state accepts an extra electron and becomes an anion.

It's like measuring how happy an atom is to grab and hold onto a passerby electron. Since it's all about a single's atom's desires, electron affinity is a property that makes sense only when you're looking at isolated atoms.