ISAT Preparation Chemistry Atoms, Molecules, and Compounds Vocabulary AtomMoleculeCompoundProtonNeutronElectronNucleus Chemical Formula Chemistry Atom smallest unit of matter Maintains the same properties of a pure substance Example copper penny Molecules atoms that are combined together make up molecules Ex. H 2 O, CO 2, H 2 O 2, CO, NO 2, N 2 O Chemistry Chemistry Compound is a pure substance made up of two or more atoms Bunch of the same molecules make up a compound Atoms are made up of sub-atomic particles that have their own properties Chemistry Chemistry Inside the nucleus core of atom Proton positive charge and has weight Neutron neutral or no charge and has weight Outside the nucleus Electrons negative charge and has no weight Chemistry 1.What are atoms? 2.What is the difference between molecules and compounds? 3.What charge does a proton and an electron have? 4.Which of the following particles has no weight? Chemistry Make Molecules Black CarbonWhite Hydrogen Red OxygenBlue Nitrogen A.H 2 OB. NH 3 C. CH 4 D. O 2 E. N 2 F. CH 3 OH G. H 2 O 2 H. C 2 H 4