What is the percent by mass of a solution that contains 7 g of potassium nitrate in 345 mL of water?

Why do consumers feel warmer after eating a meal

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

Suppose you have designed a new thermometer called the x thermometer. on the x scale the boiling point of water is 129 ? x and the freezing point of water is 13 ? x. part a at what temperature are the readings on the fahrenheit and x thermometers the same?