* "Forces that hold atoms together in molecules" refer to intramolecular forces, like covalent or ionic bonds.

* "Forces that hold a gas together" refer to intermolecular forces, like van der Waals forces or hydrogen bonds.

The reason intramolecular forces are stronger than intermolecular forces is because:

* Intramolecular forces involve the sharing or transfer of electrons between atoms, creating a strong electrostatic attraction that holds the atoms together in a stable molecule.

* Intermolecular forces are weaker attractions that occur between molecules due to temporary fluctuations in electron distribution or permanent dipoles. These forces are much weaker than the forces that hold the atoms together within a molecule.

Here's a simple analogy:

Imagine you have two people holding hands (representing atoms in a molecule). This handhold is strong and difficult to break (representing an intramolecular bond). Now imagine you have a large group of people all loosely connected by a network of ropes (representing intermolecular forces). These ropes are much weaker and easier to break than the handhold.

In summary:

The forces that hold atoms together in molecules (intramolecular forces) are stronger than the forces that hold molecules together in a gas (intermolecular forces) because the former involve a stronger electrostatic attraction between atoms due to electron sharing or transfer, while the latter are weaker attractions between molecules.