Part (a): Chalk has the chemical formula: CaCo₃ From the periodic table: mass of Ca = 40 grams mass of Co = 58.9 grams Therefore: molecular weight of chalk = 40 + 3(58.9) = 216.7 grams
Part (b): Advantages of M<span>andeleev's periodic table: 1- Could predict the properties of elements easily based on its position in the periodic table 2- Elements were arranged systematically in order of increasing atomic mass which helped in the study and classification of elements 3- Even after the discovery of noble gases, no major changes needed to be done to the periodic table. Noble gases were inserted easily 4- He left room for other undiscovered elements based on his systematic approach in writing the table
:The combination of the two galaxies then forms what appears to be an elliptical galaxy as the arms begin to disappear. The merger of gasses creates new stars, and the new shape becomes more elliptical, globular, or sometimes irregular.
