Moles and Grams: H.W.

What are the molecular weights of the following compounds?

  1. H2O
  2. NaOH

Calculate the following:

  1. How many moles are in 22 grams of argon?
  2. How many grams are in 88.1 moles of magnesium?
  3. How many moles are in 2.3 grams of phosphorus?
  4.  How many grams are in 11.9 moles of chromium?



October Project

  • Each group will be responsible for a class presentation on their assigned topic, where they will explain whom the scientist was, what led the scientists to perform the experiment, describe what the experiment consisted of in detail, and the findings and later contributions of the experiment to the atomic structure of he atom.
  • Each group will also be responsible for constructing a model that illustrates their presentation.atom-light-640x360

Group 1: J.J. Thomson’s experiments with cathode ray tubes.

Group 2: Ernest Rutherford’s gold foil experiment.

Group 3: The Rutherford experiment by Hans Geiger and Ernest Marsden that resulted in the discovery of the atomic nucleus.

Group 4: James Chadwick’s discovery of the neutron.

Group 5: Types of radiation ( Alpha, gamma, and beta)



Average Atomic Mass: H.W

Follow the link below and after watching the video provided answer questions 2 and 3 found below the video.

Calculate the following Average atomic mass remember to show your work:

  1. Neon has two major isotopes, Neon-20 and Neon-22. Out of every 250 neon atoms, 225 will be Neon-20 (19.992 g/mol), and 25 will be Neon-22 (21.991 g/mol). What is the average atomic mass of Neon?
  2. In a sample of 200 Chlorine atoms, it is found that 151 are Cl-35 (34.969 amu), and 49 are Cl-37 (36.966 amu). What is the average atomic mass of Chlorine?
  3. Without doing any math, are there more Bromine-79 atoms or more Bromine-80 atoms on earth? (Hint: look at the periodic table.)

average atomic mass

Organization of the Periodic Table

Please watch the video found in the link below and complete a descriptive timeline in your notebooks that indicates the various organizational failures that the periodic table underwent before the current organization. In you timeline you must include the name of the organizer and an explanation of why the proposed organization failed.

History of the Periodic Table