You are trying to determine the identity of an unknown metal object using density. You measure the volume by displacement using a graduated cylinder. The initial volume is 14.7 mL, and the final volume is 23.5 mL. The mass is measured using a balance and is determined to be 68.895 g. The calculation you use to find the answer is: $$

The formula you use is Density = (mass) / (volume) .

The calculation for this particular object is

Density = (68.895 g) / (23.5 mL - 14.7 mL)

Density = (68.895 g) / (8.8 mL)

Density = 7.8 g/mL

multiply 2kg by latent heat of vap

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m