Why do science textbooks tend to focus on three states of matter rather than four?

Let the ed50 of a recreational drug be defined as the amount required for 50% of a test group to feel high or get a buzz. if the ed50 value of ethanol is 470 mg/kg body mass, what dose would a 70 kg party goer need to quickly consume in order to have a 50% chance of getting a buzz? 235 mg 470 mg 32,900 mg 35,000,000 mg

How many moles of bromine are needed to produce 3.23 moles of potassium bromide

Which proportionality applies to avogadro’s law?