Today’s #STEMsigns are crystal, gem, lattice, and unit cell!
*Signs shown on #STEMsigns are seen and used by the community and are not created by Atomic Hands. We encourage you to evaluate the sign and adopt or discard it; or develop a new sign!
[Video Description: Barbara, a white woman wearing a black long-sleeve shirt, is standing with a grey background. White font appear on the top left as Barbara signs crystal, gem, lattice, and unit cell. Images appear on the top right as Barbara signs: a crystal on a purple stand; green and purple dots that form a cube; unit cell and crystal lattice illustrations; crystal and glass patterns.]
Transcript: Today’s #STEMsigns are crystal, gem, lattice, and unit cell! Many matters are made up of tiny parts called atoms. When the atoms are arranged in a repeating pattern, we have a crystal. What does a crystal look like on the atomic level exactly? The atoms are arranged in a lattice. If we look closely at the lattice, we will see sections that look identical and repeat. The smallest of these sections is called a unit cell. A lattice is built up of many, many unit cells. Each atom in the lattice has either weak or strong bonds with the adjoining atoms. The number and strength of these bonds determine whether the crystals are hard or soft. Most matter that is not alive is made up of crystals. Common substances such as sugar and salt are made of crystals. So are metals such as gold, silver, copper, and iron. Gems, or valuable mineral or mineral-like substances in a cut and polished form, such as diamonds and emeralds, can also be crystals. However, some materials that seem solid, like glass, are not made of crystals. Its molecules are not arranged in any particular pattern. The way a substance’s atoms or molecules are joined together creates a crystal’s shape. Crystals form in many different shapes. However, all crystals of the same substance have the same unit cell shape. For example, salt molecules join together to form a cube-shaped unit cell. Sugar crystals are column-shaped and slanted at the ends. Quartz crystals are six-sided columns. When we think of gems, we will probably think of diamonds, rubies, and emeralds, right? Did you know that pearls are gems as well?! Do you think the sign for “gem” should be used for all kinds of gems, including pearls, or do you think there should be a different sign for each gem or group of gems? Your thoughts?
#STEMsigns #deaf #stemeducation #stem
