The amount of matter in an object is said to be its mass. The SI base unit of mass is kilograms i.e. 
.
The mass of the object = 
(given)
For converting lbs to kg:
So, 
Hence, the mass of 
object in kilograms is 
.
Building a tower out of magnetic blocks and water vapor condensing on a bathroom mirror are only physical changes.
A physical change is easily reversible. It does not involve a change in the composition of a substance.
A tower built out of magnetic blocks can easily be pulled apart and water that condensed on a bathroom mirror can easily change back to vapour by heating.
All these are possible because the both processes are only physical changes.
Learn more: brainly.com/question/6284546
Chemistry is relevant in everyday life because it is present in your cleaning solutions, your shower products, and is present in baking, and etc.
The answer is glass is the easiest to recycle
