The density of balsa wood is about 170 kg/m³. convert to g/cm³. why do you think balsa wood, rather than oak or ash, is commonly used for building models?

If the density of balsa wood is about 170 kg then in grams it would be 170000. I've used balsa wood before and its great for models because it's strong and has a flexible threshold that doesn't snap unlike popsicle sticks sometimes.

Density=170 kg/m³
170 Kg/m³=(170 Kg/m³)(1000 g/1 kg)(1000000 cm³ /1 m³)=0.17 g/cm³

the density of balsa wood would be 0.17 g/cm³

I think balsa wood, rather than oak or ash, is commonly used for building models because the density of balsa wood is lower than oak or ash, therefore balsa wood is light and easily shaped and cut with hands tools. 

Density of oak= 0.76 g/cm³
Density of ash= 0.6 g/cm³