Brainliest: Find the mass of 7.20 dm^3 of ammonia (NH3) (measured at room temperature and pressure). Give explanation too, thank you

The is a particle with one unit of positive charge a. proton b. positron c. electron d. nucleus awnser quick it is a important science test!

How many miles of water are produced if 5.43 mol pbo2 are consumed

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