It's about one-ninetieth as heavy as a Grain of Salt.
In other words, the weight of a Grain of Salt is 90.90 times 641 nanograms.The mass of a grain of salt is approximately 58,500 nanograms. Salt consumption varies widely by country; the people of the United States consume a combined total of about 2,730,000,000,000,000,000.0000000000000000000000 nanograms of salt each year.
It's about one-five-hundredth as heavy as a Poppy Seed.
In other words, 641 nanograms is 0.0021 times the weight of a Poppy Seed, and the weight of a Poppy Seed is 480 times that amount.(Papaver somniferum)
Fifty percent oil by weight, a poppy seed weighs approximately 300,000 nanograms. The true pigment of a poppy seed is brown in color, while the characteristic bluish color is an optical illusion caused by a layer of calcium oxalate crystals refracting light rays.
It's about one-nine-hundred-fiftieth as heavy as a Grain of Sugar.
In other words, 641 nanograms is 0.00103 times the weight of a Grain of Sugar, and the weight of a Grain of Sugar is 971 times that amount.(a.k.a. white sugar, a.k.a. white refined sugar, a.k.a. table sugar, a.k.a. sucrose, a.k.a. saccharose)
A grain of sugar weighs approximately 625,000 nanograms. Sugar consumption varies widely by country; the average citizen of the United States consumes about 61,200,000,000,000 nanograms of sugar each year.
It's about one-five-thousand-five-hundredth as heavy as a Sesame Seed.
In other words, 641 nanograms is 0.000176 times the weight of a Sesame Seed, and the weight of a Sesame Seed is 5,680 times that amount.(Sesamum indicum)
A sesame seed weighs approximately 3,640,000 nanograms. The McDonald's Big Mac sandwich, which is well-known for its sesame seed top bun, accounts for the consumption of an estimated 2,010,000,000,000,000.0000000000000000000 nanograms of sesame seeds each day.
It's about one-six-thousand-five-hundredth as heavy as a Grain of Sand.
In other words, the weight of a Grain of Sand is 6,700 times 641 nanograms.(medium grain)
With tremendous variety in the size of grain and the component material, grains of sand weigh an average of 4,400,000 nanograms. In 2007, a team of seven in Myrtle Beach created the world's tallest sandcastle, which measured 15.10 m (49.55 ft) in height.
It's about one-forty-five-thousandth as heavy as a Grain of Rice.
In other words, the weight of a Grain of Rice is 45,000 times 641 nanograms.(long grain; 14% moisture content)
A single long grain of rice weighs an average of 29,000,000 nanograms. A staple through most of human history, archaeological evidence indicates that the earliest rice cultivation was about 11,500 years ago.
It's about one-three-hundred-fifty-thousandth as heavy as a Raindrop.
In other words, the weight of a Raindrop is 300,000 times 641 nanograms.(a.k.a. drop, a.k.a. droplet) (average)
The weight of a raindrop depends heavily on the type of weather, but averages about 200,000,000 nanograms. The familiar teardrop shape of a raindrop is actually an optical illusion, caused by the reflection of the light and the motion of the drop.