1) Why could most elements be arranged in order of increasing atomic mass but a few could not? 2) What is the reason for chemical periodicity, why did similar properties repeat?

What is a scientific theory? a. a scientist's guess about how something works b. the results of an experiment obtained using the scientific method c. a proven fact that will never change d. an idea that is backed by data from many sources

What is the correct name for the compound cocl3? a) cobalt(i) chloride b) cobalt(i) chlorate c) cobalt(ii) chlorate d) cobalt(iii) chloride

What are the two major rules associated with polarity