Here's a breakdown of the key differences between atoms and molecules:

Atoms:

* The fundamental building blocks of matter: Atoms are the smallest unit of an element that retains the chemical properties of that element.

* Made of subatomic particles: Atoms consist of protons, neutrons, and electrons. Protons and neutrons are located in the nucleus, while electrons orbit the nucleus.

* Examples: Hydrogen (H), Oxygen (O), Carbon (C), Helium (He)

Molecules:

* Two or more atoms bonded together: Molecules form when two or more atoms chemically bond together.

* Can be made of the same element: For example, oxygen gas (O₂) is a molecule composed of two oxygen atoms.

* Can be made of different elements: For example, water (H₂O) is a molecule made of two hydrogen atoms and one oxygen atom.

* Have different properties than the individual atoms: The properties of a molecule are often very different from the properties of the individual atoms that make it up. For example, water is a liquid at room temperature, while hydrogen and oxygen are gases.

* Examples: Water (H₂O), carbon dioxide (CO₂), glucose (C₆H₁₂O₆), DNA

Here's an analogy:

Think of LEGO bricks. A single LEGO brick is like an atom. You can use it to build things, but it's pretty basic on its own. When you connect multiple LEGO bricks together, you've created a molecule – a more complex structure with its own unique properties.