2. Platinum metal has a density of 21.4 g/mL. If the block measures 3 cm, by 0.03 m, by 40 mm how much does it weigh in milligrams?

80mg

Explanation:

Given parameters:

Density of Platinum metal = 21.4g/mL

Dimension of the metal  = 3cm by 0.03m by 40mm

Unknown:

Weight of the metal in milligrams?

Solution:

Density is the mass per unit volume of a substance.

Mathematically;

          Density  =

Volume of the platinum metal  = l x w x h

 Let us convert the dimension of the metal to the same unit;

            3cm x 0.03m x 40mm

    convert to cm;

           100m = 1cm

           0.03m  =   = 0.0003cm

     -- 40mm;

            1mm = 0.1cm

           40mm  = 40 x 0.1  = 4cm

Volume of the metal  = 3 x 0.0003 x 4  = 0.0036cm³

1mL = 1cm³; so volume  = 0.0036mL

     Mass of the metal  = 21.4 x 0.0036  = 0.08g

       1g  = 1000mg

     0.08g  = 0.08 x 1000 = 80mg

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

if you mean hydrogen and oxygen then water is the product