What makes an element an element?

Answer	An element is a pure substance made of one kind of atom. It keeps its identity because its atoms have the same proton count (atomic number). WHY IT MATTERS: Material selection (aluminum, copper, titanium) depends on element-level properties. AIRCRAFT EXAMPLE: Aluminum structure vs copper wiring: different elements, different properties. MEMORY AID: PEN: Proton = Element = Number. EASA TIP: Identity questions almost always point to protons/atomic number.
Difficulty	Easy
Lesson	2.1.1 Nature of Matter
Module	Module 2.1
Tags	EasyElementsModule 2.1