Noble gas:
Oxygen
Chlorine
Or Krypton

Noble gases are the most reactive elements on the periodic table. a. true b. false

When a beta particle is emitted, the mass number of the nucleus a. decreases by one b. increases by one c. remains the same d. decreases by two

Dumbledore decides to gives a surprise demonstration. he starts with a hydrate of na2co3 which has a mass of 4.31 g before heating. after he heats it he finds the mass of the anhydrous compound is found to be 3.22 g. he asks everyone in class to determine the integer x in the hydrate: na2co3·xh2o; you should do this also. round your answer to the nearest integ