Once students understand the basic structure of atoms, they then focus on how atoms are like children’s building blocks, forming molecules and compounds by combining with other atoms to create all of the matter in the universe.
Prepared hands-on materials, full year grade-specific curriculum, and personalized live professional development designed to support mastery of current state science standards.
Libyan Desert Glass
In 1996, an Italian scientist noticed an unusual gem in one of Tutankhamen’s necklaces. Tutankhamen was an Egyptian pharaoh who ruled between 1331-1323 BC. He is sometimes called King Tut. The Italian scientist was interested in a yellow- green gem that he saw in King Tut’s necklace. When the gem was tested, it was found to be glass. However, it was older than the oldest Egyptian civilization.
What Formed the Glass?
How this glass was made is a question that scientists are still trying to answer. It came from a stretch of desert in Africa called the Libyan Desert. More than one thousand tons of this kind of glass have been found there. Scientists have dated this glass to be more than 26 million years old. It is generally yellow, and it can be translucent or almost opaque. Translucent substances can partly be seen through. Opaque substances block all light.
Scientists believe that this Libyan Desert glass may have formed when a meteorite hit Earth or when a comet from space exploded in Earth’s atmosphere. Both of these events would have provided the extreme temperatures necessary to change the desert sand into glass.
Glass’s State of Matter
Glass is unlike any material on Earth. Scientists sometimes refer to glass as a rigid liquid because it isn’t quite a solid, and it’s not exactly a liquid. This is because of the extreme temperatures that form glass.
Whether a substance is a solid, liquid, or gas depends on the amount of thermal energy present. All matter has thermal energy, which is the motion of atoms and molecules in a substance or object as its temperature increases. Temperature is a measure of heat. Heat is energy transferred when two objects or systems are at different temperatures. It always transfers from hotter substances to cooler substances. The faster that atoms and molecules move, the more thermal energy they have and the warmer they become.
Sand is a solid at room temperature. The atoms in a solid are closely packed together. They are always moving, but because of how close they are, they can only vibrate in place. They cannot move past one another. Because of this, solids keep their shape until something changes them.
When thermal energy is added to solids, the atoms or molecules begin to move more quickly. When enough energy is added, they will expand and become a liquid. The temperature at which a substance changes from a solid to a liquid is a property of matter called its melting point.
This is what happens when lightning or a meteor comes into contact with sand. When sand is heated to such a high temperature that it melts, it becomes a liquid. Its atoms and molecules are moving much faster, and can slide past one another. Different substances have different melting points depending on how much energy is needed to change them from a solid to a liquid. This in turn depends on the kind of atoms that make them up.
KnowAtom incorporates formative and summative assessments designed to make students thinking visible for deeper student-centered learning.
Discover hands-on screens-off core science curriculum for student centered K-8 classrooms. KnowAtom supports classrooms with all hands-on materials, curriculum, and professional development to support mastery of the standards.
