Mass can change during a nuclear reaction. Imagine you're building LEGO structures, and sometimes, when you snap them together, they change in a magical way! That's kind of how nuclear reactions work. This change in mass is what drives nuclear reactions.

Ever tried measuring the weight of a raindrop with a bathroom scale? That's why in nuclear physics, using kilograms doesn’t really work out. Nuclei are tiny, and their mass values would be sooo small in kg!

🍪 Enter: The Atomic Mass Unit (AMU or just u)

• What is it? It’s basically the mass of a Carbon-12 atom divided by 12.
• Exact Value: 1u = 1.66053906660(50) x 10⁻²⁷ kg (Imagine it as one tiny sprinkle on a cupcake!)

💡 The weird numbers in brackets like (50) just tell us the measurement might be a teensy bit off, but it's super close!

Ever heard of Einstein's famous equation E=mc²? Basically, energy and mass are two sides of the same coin.

In nuclear physics, we can measure mass in terms of its energy equivalent (MeVc⁻²). Think of it like measuring the length of a soccer field in the number of pizzas it can hold! (Random, but fun!)

• Proof Time: An energy of 931.5MeV is pretty much the same as 1.66 x 10⁻²⁷ kg. Magic, right?

📌 Here's a Quick Rundown

• Proton: 1.673 × 10⁻²⁷ kg = 1.007276u = 938MeVc⁻²
• Neutron: 1.675 × 10⁻²⁷ kg = 1.008665u = 940MeVc⁻²
• Fun Fact: Neutrons are like the older siblings, slightly heavier than protons!