2. The system used in the U.S. is not as logical as that used in other countries (like Great Britain, France, and Germany). In these other countries, a billion (bi meaning two) has twice as many zeros as a million, and a trillion (tri meaning three) has three times as many zeros as a million, etc. ZerosU.S. & scientific communityOther countries 3thousandthousand 6millionmillion 9billion1000 million (1 milliard) 12trillionbillion 15quadrillion1000 billion 18quintilliontrillion 21sextillion1000 trillion 24septillionquadrillion 27octillion1000 quadrillion 30nonillionquintillion 33decillion1000 quintillion 36undecillionsextillion 39duodecillion1000 sextillion 42tredecillionseptillion 45quattuordecillion1000 septillion 48quindecillionoctillion 51sexdecillion1000 octillion 54septendecillionnonillion 57octodecillion1000 nonillion 60novemdecilliondecillion 63vigintillion1000 decillion

3. 1 mL = 1 cm3 1 milliliter is the same volume as 1 cubic centimeter. 1 mL of water has a mass of approximately 1 g The mass of 1 milliliter of water is approximately 1 gram. 1 L of water has a mass of approximately 1 kg The mass of 1 liter of water is therefore approximately 1 kilogram. 1 m3 of water has a mass of approximately 1 t There are 1000 liters in a cubic meter, so the mass of 1 cubic meter of water is approximately 1000 kilograms or 1 metric ton. The mass of a nickel is 5 g A US nickel weighs 5 grams, and a penny weighs 2.5 grams. A typical doorknob is 1 m high Although there's no precise standard for doorknob heights, they're often about 1 meter above the floor. The diameter of a CD or DVD is 12 cm A CD or DVD is 12 centimeters (120 millimeters) across. The diameter of the center hole is 15 millimeters. 1 ha is 1002 m2 1 hectare is 10 000 square meters, equivalent to the area of a square 100 meters on a side. A football field is about 100 meters long, so imagine a square the length of a football field on each side, and th

6. Particle TypeTypical Diameter(mm)Volume relative to cloud drop Cloud Droplet0.0121 Large Cloud Droplet0.1579 Mist Droplet0.572,300 Drizzle Drop1.21,000,000 Raindrop3.015, 600,000 Large Raindrop6.0125,000,000 Raindrop the Alpaca