Which rules are violated in the following electronic configuration 1s2 2s3

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole

Which of the following is a physical property flammability heat of combustion solubility and toxicity

What two factors can affect the properties of a hydrocarbon? a. the number of its carbon atoms and the number of single bonds b. the number of its carbon atoms and the arrangement of its atoms c. the arrangement of its atoms and the number of its double bonds