CHEM 1A03 Chapter Notes - Chapter 2: Hong Kong Diploma Of Secondary Education, Francium, Krypton

• School: McMaster University
• Department: Chemistry
• Course: CHEM 1A03
• Professor: David Brock

Document Summary

Element: a pure chemical substance consisting of a single type of atom. Atom: the smallest piece of an element that has the chemical properties of that element. Conductivity of electricity good conductor of electricitypoor conductor of electricity. Semi-metals/metalloids: elements with properties in between metals and non-metals. Structure: consists of a small, dense nucleus (protons and neutrons) surrounded by a cloud of electrons. Ax, where a is mass number, z is atomic number and x is. Atomic number: number of protons in an atom. Mass number: total number of protons and neutrons. Isotopes: atoms of the same element with di5erent number of neutrons. Have same chemical properties but di5erent physical properties. Relative isotopic mass: mass of isotope relative to carbon, where carbon has mass 12. Relative atomic mass (ram): average mass of isotopes, weighted by abundance of isotopes. Electron shells: possible positions (energy levels) of electrons in an atom.