Density = Mass/Volume
So, given mass = 20 g and volume = 40 cm^3
By substituting in above equation, Density = 20/40 = 0.5 g/cm^3
Hope it helps.
Answer:
none of the above or screwdriver
Answer:
Explanation:650
colour* wavelength (nm) energy (eV)
red 650 1.91
orange 600 2.06
yellow 580 2.14
green 550 2.25
