The idea of the atom as the building block of matter has developed over time. What was thought of as a single particle about 1 × 10‾¹⁰ m across is now known to be a collection of smaller particles.
Elysse Bell is a finance and business writer for Investopedia. She writes about small business, personal finance, technology, and more. Samantha (Sam) Silberstein, CFP®, CSLP®, EA, is an experienced ...