CHEM 1010U Chapter Notes - Chapter 2: Chemical Substance, Chemical Formula, Weighted Arithmetic Mean
Document Summary
Understanding matter: element: a basic substance that can"t be simplified, atom. Can"t be chemically changed or broken down into something simpler. Hydrogen, oxygen, etc. (found on periodic table) The basic building blocks of ordinary matter. Can join together to form molecules which form most of the objects around you. Is made up of electrons, protons, and neutrons. The 3 laws: law of mass conservation. When combustion is carried out in a closed container, the mass of the starting reactants equals that of the products . Mass is neither created nor destroyed in chemical reactions: law of definite proportions. Different samples of a pure chemical substance always contain the same proportions of elements by mass: h2o. 32/44. 01 x 100= 72. 7: law of multiple proportions. Elements can combine in different ways to form different substances, whose mass ratios are small whole number multiples of each other. There were discreet units on atoms that could combine in different ways.
