CHEM 151 Lecture Notes - Lecture 3: Molar Mass, Gas Constant, Covalent Bond

• School: University of Arizona
• Department: Chemistry
• Course: CHEM 151
• Professor: kumirov

Document Summary

Fundamental assumption: substances in our world have different properties because they are made of particles with different compositions and structures. Atomic model of substances: the particles that compose the substances in our surroundings have internal structure. They are made up of small units called atoms which are held together by strong attractive forces called chemical bonds. A molecule"s composition and structure determines how the molecule will interact with other particles of similar or different type. Elementary substances: substances that cannot be decomposed into simpler stable substances by any physical or chemical procedures. Chemical compounds: substances that can be split into two or more simpler stable substances by inducing a chemical reaction. Metals: usually solid at room temp, conduct heat and electricity well. Non-metals: usually gases at room temp, conduct heat and electricity poorly. Metalloids: share some properties of metals and nonmetals. Chemical formula: a symbol that conveys information about the atomic composition of a given substance.