Endeleev saw trends in the physical and chemical properties of elements when he organized them by

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.

since electrons are negative the answer is neagtaive