How many moles of ammonia gas are there in 500cm3 of the gas?​

Compare and contrast physical changes with chemical changes.

Which of these is an example of pseudoscience? a) predicting the time of sunrise based on data on position of earth b) predicting the date of the moon phases based on data on position of earth c) predicting eclipses based on the position of the sun and the moon d) predicting future events in a person's life based on the position of the moon

How many atoms or molecules are there in a mole of a substance?