Before 2006, Pluto was classed as the ninth planet in our solar system. Since then, it's been classed as a dwarf planet

 Before 2006, Pluto was classed as the ninth planet in our solar system. Since then, it's been classed as a dwarf plane

Over the ages, people have attributed many facts to numbers.

Numerology, superstition, important dates, and so many other things cling to various numbers, which in some cases gives them great significance!

Today let’s take a look at ten fun facts about the number nine.

A two-dimensional shape with eight sides is called either an enneagon or a nonagon, while a three-dimensional shape with eight faces is called an enneahedron or a nonahedron. While the prefix ennea- is sometimes used in scientific terms to denote the number nine, it’s not commonly used. That being said, a group of any nine things is called an ennead.

There used to be nine planets in the solar system, but this number was reduced to eight in 2006. No, a planet didn’t explode, but Pluto was downgraded from a planet to a dwarf planet.

The chemical element with the atomic number nine is fluorine. Fluorine belongs to the 17th group, the halogens, on the periodic table of elements. In its natural state, it’s a highly toxic gas and is extremely reactive to nearly all other elements. Fluorine is found naturally within the mineral fluorite, which once refined is used to enrich uranium.

Pregnancy in humans typically lasts for nine months, split up into three trimesters of three months. This is, of course, a very rough guideline, as babies can be born from 37 weeks to more than 42. Generally, the closer to the 37-week mark that a baby is born, the more serious health issues it could have, while those born between weeks 39 and 41 are the healthiest.