General Introduction›Units and Scale›Getting a sense of scale
Lesson 01 of 01
Getting a sense of scale
Key Concepts
- Atoms
- Scale and size
- Metre
- Centimetre
- Millimetre
- Micrometer
- Nanometre
- Angstrom
- Unit prefixes
- Cells and DNA
Lesson notes
It's one thing to know atoms are small — it's another to truly feel the scale. This video takes you through a series of comparisons and calculations that make the size of an atom genuinely imaginable, from grains of sand to human hairs to the width of a nucleus. You'll also see how scientists use nanometres and standard form to express these measurements, and why scale matters across chemistry and nanotechnology.
What You Will Learn
01:35How to define and convert between metres, centimetres, millimetres, micrometres, and nanometres.
01:57Why the metre is too large a unit for atoms and why subdivisions are needed.
02:41How scientists use factors of a thousand to create standard metric subdivisions with prefixes.
06:39How the size of an atom (0.1 nm) compares to everyday objects, cells, and DNA strands.
06:49What the angstrom unit is and why it does not appear in GCSE exam papers.
08:06How to use the scale of a fingerprint ridge to visualise the number of atoms that fit across it.
