<u>Given:</u>
Calculated density values-
Aluminum = 2.7 g/cm3
Copper = 9.0 g/cm3
Iron = 7.9 g/cm3
Titanium = 4.8 g/cm3
Unknown sample mass = 9.5 g
Sample volume = 2.1 cm3
<u>To determine:</u>
The identity of the unknown sample
<u>Explanation:</u>
'Density' is a physical parameter which can be used to identify the nature of the unknown substance. 
Density = Mass/Volume
For the unknown sample
Density = 9.5 g/2.1 cm3 = 4.52 g/cm3
This matches closely with the calculated density of titanium
Ans: The unknown substance is made of titanium
 
        
             
        
        
        
Copper is an brown-orange color which it's atomic number is 29. With high thermal and electricity conductivity with it's smooth surface.
 
        
             
        
        
        
Answer:
"Avogadro's law is an experimental gas law relating the volume of a gas to the amount of substance of gas present. The law is a specific case of the ideal gas law. A modern statement is: Avogadro's law states that "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules."
 
        
                    
             
        
        
        
As what we can see on the graph of the Boyle's Law, we can imply that volume and pressure are inversely proportional. The gas law furthermore explains that at this condition, the temperature must be held constant. The law can be furthermore be explained using the equation:
PV = k
        
             
        
        
        
Sodium fluoride- to brush teeth
Citric acid- orange juice for breakfast 
Sodium hydroxide- cleaning agent