Biggest and smallest things in the world across various categories:

Biggest:

1. Mount Everest: Tallest mountain above sea level, located in the Himalayas on the border of Nepal and China.

2. Pacific Ocean: Largest ocean on Earth, covering approximately one-third of the planet's surface.

3. Blue Whale: Largest animal ever known to have existed, with adults reaching lengths of up to 30 meters.

4. Sahara Desert: Largest hot desert in the world, spanning over 9 million square kilometers across North Africa.

5. Amazon Rainforest: Largest tropical rainforest in the world, covering approximately 5.5 million square kilometers across South America.

6. Great Barrier Reef: Largest coral reef system in the world, located off the coast of Queensland, Australia.

Smallest:

1. Nanoscale Objects: At the nanoscale level, various particles and structures, such as nanoparticles and nanotubes, are considered some of the smallest things in the world, often measured in nanometers (one billionth of a meter).

2. Bacteria and Viruses: Microscopic organisms like bacteria and viruses are some of the smallest living entities on Earth, with sizes ranging from a few nanometers to a few micrometers.

3. Atoms and Subatomic Particles: Atoms, the basic building blocks of matter, are incredibly small, with diameters typically measured in picometers (one trillionth of a meter). Subatomic particles like electrons, protons, and neutrons are even smaller components of atoms.

4. The Nucleus of an Atom: Within an atom, the nucleus contains protons and neutrons tightly packed together, making it one of the smallest structures known to science.

5. Quarks: Quarks are elementary particles that make up protons and neutrons, among other particles. They are some of the smallest known building blocks of matter, with sizes on the order of femtometers (one quadrillionth of a meter).

These are just a few examples of the biggest and smallest things in the world, and there are many more fascinating extremes to explore across different fields of science and nature.