Atomic mass unit

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/atomic-mass-unit

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the formal definition?1/12 the mass of an unbound neutral atom of carbon-12
2. What is the SI equivalent?Approximately 1.66053906660 × 10^-27 kilograms
3. What is an atomic mass unit and why do we use it?It is a unit that measures the mass of tiny atoms, defined as one-twelfth the mass of a carbon‑12 atom. It gives a standard for comparing masses.
4. How do scientists measure the mass of atoms?Scientists use mass spectrometers that separate charged particles by their mass‑to‑charge ratio. They use electric and magnetic fields or timing the particles’ flight to measure masses to many decimal places.

Isotope: Atoms of the same element with identical numbers of protons but differing numbers of neutrons, leading to different masses.
Nuclide: A distinct type of atomic nucleus characterized by a specific number of protons and neutrons.
Mass Spectrometry: An analytical technique used to measure the mass-to-charge ratio of ions, enabling precise mass determination of atoms and molecules.
Stoichiometry: The calculation of relative quantities of reactants and products in chemical reactions based on balanced chemical equations.