What is the mole fraction of NaBr in an aqueous solution that contains
20.1% NaBr (weight/weight %)?
Molar Mass
NaBr: 102.89 g/mol
H20: 18.016 g/mol

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?

Light waves are as they pass through the

Asubstance is held in an open container. its particles move past one another at random speeds but do not leave the container. heat is removed from the system, and the particles slow down. when enough heat is removed, the particles no longer have enough speed to overcome the weak attractive forces between them. when this happens, the substance enters its solid state. the process described above is known as .