CHE 1300 Quiz: EXAM 2 Study Guide
Document Summary
400 bc proposed: all matter composed of 4 fundamental substances: fire, earth, water, air. Cannot be broken down into 2 or more simpler substances. Could mean a single atom (ar or n) Could mean molecules of an element (h2) Could mean atoms of elements are present in some form(sodium in human body) Elements are made of tiny particles called atoms (tiny, head, indivisible, spheres) atoms. All atoms of a given element are identical. Atoms of one element can combine w/atoms of other elements to form compounds. Also need positive particles that balance the negative charge. Thomson"s plum pudding model = alpha-particles go right through. Nuclear model - volume of atom is mostly empty space. Different # of neutrons = isotope! (will have same # of protons, because that is it"s identity! Slide 27 is what she likes to use on her test. Dalton stated all atoms of a given element have the same mass.
