<span>B.by arranging the elements according to atomic number instead of atomic mass</span> awnser is B
        
                    
             
        
        
        
Answer:
1.5g/cm³
Explanation:
density=mass÷volume
mass= 1.5kg (<em>c</em><em>h</em><em>a</em><em>n</em><em>g</em><em>e</em><em> </em><em>i</em><em>n</em><em>t</em><em>o</em><em> </em><em>g</em>) = 1500g
volume of the cube = 10×10×10 = 1000cm³
density= divide 1500g÷1000cm = 1.5g/cm³
<h2>
Density= 1.5g/cm³</h2>
YOUR WELCOME!
 
        
             
        
        
        
Answer:
oxygen and silicon, both are common 
 
        
             
        
        
        
1.Start with the number of grams of each element, given in the problem.
2.Convert the mass of each element to moles using the molar mass from the periodic table.
3.Divide each mole value by the smallest number of moles calculated.
4.Round to the nearest whole number. This is the mole ratio of the elements and is.
 
        
             
        
        
        
Hey There!:
2 C2H2 + 5 O2 = 4 CO2 + 2 H2O
2 moles C2H2 ----------- 5 moles O2
35.0 moles C2H2 ------- moles O2
moles O2 = 35.0 * 5 / 2
moles O2 = 87.5 moles
hope this helps!