A hydrometer is made up of a tube of diameter 2.3 cm. The mass of the tube and its contents is 80.0 g. If it floats in a liquid of density 800.0 kgm .. calculate the depth to which it sinks ​

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.