If the density of tin is 7.26g/cm. what is the thickness of a peace of tin foil that measures 5.00cm by 5.00cm and has a mas of 2.722g

We know that  

Density = mass / volume  

And volume = L*W*H (thickness)

First calculate the volume of foil as follows:

Density = mass / volume  

Volume = mass / density  

= 2.722 g/ 7.26 g/ cm^3

= 0.375 cm^3

And volume = = L*W*H (thickness)

0.375 cm^3 = 5cm*5 cm * thickness

Thickness = 0.015 cm

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

yes it is balanced