What element is added to toothpaste and city water to prevent tooth decay?

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?

Butane gas reacts with oxygen gas to give carbon dioxide gas and water vapor (gas). if you mix butane and oxygen in the correct stoichiometric ratio, and if the total pressure of the mixture is 390 mmhg, what is the pressure (in mmhg) of water vapor after the reaction is completed (temperature and volume do not change).

What is the temperature in kelvin of a gas if it is allowed to expand from 1.50 l to 4.50 l? the initial temperature is 10.0°c and pressure is constant throughout the change. which equation should you use? t2= v2/v1 t1 what is the final temperature? ⇒ 849 k these are the answers.