CHEM 1127Q Lecture 4: Chapter 2 - Atoms, Ions, and Molecules

• School: UConn
• Department: Chemistry
• Course: CHEM 1127Q
• Professor: Dr. Niluka Wasalathanthri

Document Summary

Chapter 2 - atoms, ions, and molecules (continued) Positively charged particles found in the nucleus. Electrically neutral particles found in the nucleus. Negatively charged particles distributed around the nucleus. 1 amu is exactly 1/12 of the mass of 1 carbon atom. 1 amu = 1. 6605 x 10^-24 g. In grams and not kilograms because it is already such a small value. The mass of an atom in atomic mass units (amu) All atoms can be identified by the number of protons and neutrons they contain. Atoms are neutral, so it is also the number of electrons. Protons determine the identity of an element. Protons and neutrons are collectively referred to as nucleons. Atoms that have the same atomic number but different mass numbers. Or atoms that have the same number of protons but different number of neutrons. Isotopes of the same element typically exhibit identical chemical properties.