What Is Picometer?
A picometer is a very small unit of length in the metric system. It is used to measure things that are much smaller than we can see with our eyes, such as atoms, tiny parts of crystals and parts of molecules.
Because it is so small, you will mostly see the picometer in science fields like physics, chemistry and materials science, not in everyday life.
Definition
In simple words, a picometer is one trillionth of a meter.
Written as a number:
- 1 picometer = 0.000000000001 meter
- 1 picometer = 10^-12 meter
Compared to other small metric units:
- 1 picometer (pm) = 0.001 nanometer (nm)
- 1 nanometer (nm) = 1000 picometers (pm)
- 100 picometers (pm) = 1 angstrom (Å)
Typical atom sizes are around 50 pm to 300 pm, so the picometer is very useful when talking about atoms.
History / Origin
The picometer comes from the metric system, which is the main system of measurement used in science and in most countries in the world.
The word has two parts:
- meter is the base unit of length in the International System of Units (SI)
- pico is a prefix that means one trillionth, or 10^-12
The prefix pico was officially added to the SI system in the 1900s, when scientists needed names for very small and very large amounts. As physics, chemistry and crystallography grew, people started using the picometer to talk clearly about atom sizes, bond lengths and very small distances studied with x rays and electron beams.
Symbol & Abbreviation
The standard symbol for the picometer is:
- pm
Important points about the symbol:
- It uses lowercase letters p and m
- It has no dot or period after it
- It should always be written right after the number, with or without a small space, for example 120 pm
Current Use Around the World
Today, the picometer is used mainly in advanced science and technology, not in daily measurements like height or road distances.
Some common uses are:
- Physics to describe the size of atomic nuclei, electrons clouds and very small movements in crystals
- Chemistry to give bond lengths between atoms and sizes of molecules
- Materials science to measure spacing between layers of atoms in solids
- Crystallography and x ray studies to describe distances between crystal planes
- Nanotechnology to talk about changes smaller than a nanometer
Because the International System of Units is used worldwide, scientists in almost every country understand and use the picometer.
Example Conversions
Here are some simple picometer conversion examples. You can use them to understand how small a picometer is compared to other units.
| 1 pm | = 10^-12 m |
| 10 pm | = 1.0 × 10^-11 m |
| 100 pm | = 1.0 × 10^-10 m |
| 1000 pm | = 1.0 × 10^-9 m = 1 nm |
| 50 pm | = 0.05 nm |
| 200 pm | = 0.2 nm = 2 Å |
To change picometers to meters, divide by 1,000,000,000,000 (10^12). To change meters to picometers, multiply by 1,000,000,000,000 (10^12).
Related Units
These units are often used together with the picometer when talking about very small lengths.
- Meter (m) the main SI unit of length. All other length units in the metric system are based on the meter.
- Millimeter (mm) 1 mm = 0.001 m. About the thickness of a coin or a credit card.
- Micrometer (micron, µm) 1 µm = 10^-6 m. Used for cells and bacteria.
- Nanometer (nm) 1 nm = 10^-9 m = 1000 pm. Used for DNA, viruses and tiny devices on computer chips.
- Angstrom (Å) 1 Å = 0.1 nm = 100 pm. Not an SI unit but still common in chemistry and crystallography.
- Femtometer (fm) 1 fm = 10^-15 m. Used to describe the size of atomic nuclei. It is smaller than a picometer.
FAQs
How small is a picometer compared to a nanometer?
A picometer is one thousand times smaller than a nanometer. 1 nm = 1000 pm.
Is a picometer smaller than an angstrom?
Yes. 1 angstrom is equal to 100 picometers. So the picometer is the smaller unit.
What kinds of things are measured in picometers?
Picometers are used to measure atom sizes, bond lengths between atoms, distances between layers in crystals and very tiny changes in materials.
Can we see a picometer sized object with our eyes?
No. The human eye cannot see anything that small. Even normal light microscopes cannot see at the picometer scale. Scientists use special tools like x ray and electron beams instead.
Why not just use nanometers instead of picometers?
Nanometers work well for many tiny things, but sometimes scientists need to talk about even smaller changes. The picometer helps them describe these differences more clearly and exactly.
Is the picometer used in everyday life?
No. In daily life we use meters, centimeters and millimeters. Picometers are mainly for scientific work and research.
Is pm the same as picometer everywhere?
Yes. The symbol pm is accepted around the world as the standard symbol for the picometer in the SI system.