It's about one-fifth as heavy as a liter of Water
In other words, 0.000000000200 megatonnes is 0.19999440 times the weight of a liter of Water, and the weight of a liter of Water is 5.00014 times that amount.(fresh; 4° C / 39.2° F; maximum density)
Contrary to popular belief, 1 liter (0.0.264172052358148 gal) of water at 4° C / 39.2° F (its point of maximum density) weighs 0.0000000010000280 megatonnes rather than 1 kg exactly. The total volume of water on the planet Earth is about 13,590,000,000,000,000,000 (13.59 quntillion) L (3,590,000,000,000,000,000 gallons).
It's about six times as heavy as a Light Bulb
In other words, 0.000000000200 megatonnes is 5.90 times the weight of a Light Bulb, and the weight of a Light Bulb is 0.170 times that amount.(a.k.a. lamp) (for A19-size, 60w, incandescent bulb by Bulbrite; package weight)
A standard, sixty-watt light bulb weighs about 0.0000000000340 megatonnes. The tightly-coiled filament inside a bulb of this size would measure about 579mm if uncoiled and stretched out.
It's about one-tenth as heavy as a Human Brain
In other words, 0.000000000200 megatonnes is 0.1480 times the weight of a Human Brain, and the weight of a Human Brain is 6.760 times that amount.(adult)
The average weight of an adult human brain is between 0.000000001350 megatonnes. In humans and primates, sight and vision utilize about 30 different parts of the brain which together account for about half of the brain's size.
It's about eight-and-a-half times as heavy as a Battery (AA)
In other words, the weight of a Battery (AA) is 0.120 times 0.000000000200 megatonnes.(Alkaline)
An "AA" size battery weighs 0.0000000000240 megatonnes. AA batteries came into common use during World War II and were given their name by the American National Standards Institute (ANSI) Committee C18 because they were smaller than the "A" size batteries which were invented first.
It's about nine-and-a-half times as heavy as a Mouse
In other words, the weight of a Mouse is 0.110 times 0.000000000200 megatonnes.(a.k.a. "House mouse", Mus musculus) (adult)
The weight of a mouse is typically an average of 0.0000000000210 megatonnes. While most mice typically live two to three years, the Methuselah Mouse Prize — an award administered by a non-profit organization which advances aging-related research — was once awarded to a team of scientists whose research resulted in a mouse living just under five years.
It's about one-tenth as heavy as a Chihuahua
In other words, 0.000000000200 megatonnes is 0.0889 times the weight of a Chihuahua, and the weight of a Chihuahua is 11.20 times that amount.(a.k.a. Chihuahue(o) (FCI standard)
The F&d&ration Cynologique Internationale (FCI) calls for Chihuahuas to weigh about 0.000000002250 megatonnes. Relative to their body sizes, Chihuahuas have the largest brain size of any dog breed.
It's about thirteen times as heavy as a Compact disc