Place the glass apparatus on the overhead projector. Wait until a while ring of solid ammonium chloride forms where the hydrogen chloride and ammonia gases meet. The ammonia gas, having a lower ...

The equation shows that ammonium chloride (a white solid) can break down to form ammonia and hydrogen chloride. It also shows that ammonia and hydrogen chloride (colourless gases) can react to ...

The mass of hydrogen is the lowest of all the atoms. These low masses help explain why polyethylene has a low density. Another reason is that these long skinny molecules are loosely packed together.