Tritium (31h) is an isotope of hydrogen that is sometimes used to make the hands of watches glow in the dark. the half-life of tritium is 12.3 years. after 49 years, approximately how much of the original tritium remains?

If 4.8 moles of X and 3.4 moles of Y react according to the reaction below, how many moles of the excess reactant will be left over at the end of the reaction? 3X + 2Y "yields" / X3Y2 1.7 mol Y left over 1.6 mol X left over 0.2 mol Y left over 0.

Why do foods stay fresh longer when stored in an airtight container? a) The container stabilizes the temperature of the system b) Reactions that spoil food need oxygen to occur c) The container increases the pressure on the food

What is similar between Gregor's life before and after his physical transformation? A. He still supports his family financially B. He is still happy that he has a nice famiky who lives him. C. He still feels bored and unsatisfied with his life. D.

How many grams of kmno4 are required to prepare 2.000 l of. 04000m kmno4 solutin that is used in titrating na2c2o4?

Combining Boyle's law and Charles' law forms one presure-temperature-volume relationship and holds the mass of the gas constant. Which equation represents the relationship of the combined gas law?

What would you measure a cooking pot by

Is pancakes cooking on a griddle a physical or chemical change?

To determine whether a shiny gold-colored rock is actually gold, a chemistry student decides to measure its heat capacity. She first weighs the rock and finds that it has a mass of 4.7 g. She then finds that, upon absorption of 52.

In most Acid-base reactions, what type of bond (ionic or covalent) is formed between the ions of the "salt"? What happens to the electrons in this sort of bond? Are they transferred, or shared?

Many trials are not needed before a hypothesis can be accepted