CHEM 1211 Lecture Notes - Lecture 2: Atomic Number, Mass Number, Ion

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cyangoldfish931

4 Sep 2016

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Document Summary

Law of conversion of mass- matter is neither created nor destroyed in a chemical reaction. Law of de nite proportions- all the samples of a given compound have the same proportions of their constituent elements, regardless of the source or how it is prepared. Law of multiple proportions- when two elements (a and b) form two different compounds, the masses of element b that combine with 1g of element a can be expressed as a ratio of small whole numbers. Discovery of subatomic molecules: electron- thomson and milikon, orbits nucleus, negative, no real mass, proton- rutherford, located in nucleus, positive, 1 amu, neutron- chadwick, located in nucleus, neutral, 1 amu. Mass number- number of protons and neutrons, weighted average of isotopes.

Related Questions

In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound:

(a) Calculate the mass of fluorine per gram of iodine in each compound. (b) How do the numbers in part (a) support the atomic theory?

b) When all three numbers are divided with 0.15, it gives: 5, 3, and 7. So, F and I form compounds in constant, whole number ratios. This is a law of multiple proportions and goes along with Dalton’s atomic theory since the F and I atoms combine in known ratios, and the masses of atoms are constant.