Answer:
Chemical science arises in the seventeenth century from the studies of alchemy popular among many of the scientists of the time. The basic principles of chemistry are considered to be collected for the first time in the work of the British scientist Robert Boyle: The Skeptical Chemist (1661).
You need to add an attachment or something this doesnt give the needed information
The number of valence electrons = group number
e. g 1 valence electron in group IA
The relationship between the evaporation rate and the likelihood that the liquid will be flammable is its flash point number (or the lowest temperature for which the liquid ignites) and its activation energy (how much energy is required to ignite it). With volatile liquids or gases these numbers seem to be lower.
