What Things Are Made Of (1960)

[Music] our world is made of land air and water it is filled with concrete steel glass wood and many other materials although we have names for each of these different materials the scientist uses one word to describe the things we see in our world that word is matter people buses cars and buildings are made of matter mountains forests and rivers are made of matter planets and stars are also made of matter the earth and its oceans are made of matter all living things are matter all non-living things are also matter but what is matter to the scientists everything that has weight and occupies space is matter for example this metal object is matter we can see that the metal has weight the metal also occupies space we can see that it is taking up most of the space that the water occupied all matter that has a definite shape is matter in a solid state what about the air that we breathe we can't see air is air also matter the scientist can help us find out this balloon is being filled with air air is a mixture of gases do gases occupy space as we fill the balloon with air we can see that air a gas does occupy space all gases occupy space do gases have weight we will find out using a very delicate balance or scale two empty beakers on the scale exactly balance each other now we will pour bromine a gas we can see into one beaker the scale shows us that the bromine has weight all gases have weight but gases do not have a definite shape or volume as we can see by this gas now what about liquids does water fit our definition of matter let's find out we'll color the water to make it easier to see water like all other liquids does have weight and we can see that liquids also occupy space so we can say that liquids are matter liquids unlike solids have no definite shape liquids take the shape of the container that holds them a liquid a solid and a gas these are the three states of matter but the scientist is also interested in what matter is made of in the composition of matter for example this is sulfur a solid the scientist knows that each of these pieces of sulfur is made up of many tiny crystals of sulfur like this one which has been magnified so we can see it the sulfur crystal is made up of millions of smaller particles called atoms this carbon is made up of atoms of carbon all atoms are so small that we do not see individual atoms however a single atom is often represented like this an atom is made up of a center or nucleus around which small particles called electrons move any matter such as sulfur for example that is made up of atoms that are all alike is called an element sulfur is an element carbon is also an element this is powdered iron iron is an element let's look at some more common elements most of our electrical wires are made from copper copper is a common element this pot is made of aluminum another common element altogether more than 100 elements have been discovered remember that each element is matter in which all the atoms are alike in other words there are more than 100 different kinds of atoms since there are only about 100 different kinds of atoms how can there be so many different substances in the world let's imagine that we can make an atom large enough for us to see we will call this atom oxygen another element oxygen usually exists as two oxygen atoms joined together this is a molecule of oxygen most elements exist as molecules sometimes molecules are made by joining different kinds of atoms here are two hydrogen atoms we join the two hydrogen atoms with the oxygen atom this gives us an entirely different kind of matter this is a molecule of water this molecule made of different kinds of atoms is a compound water is a compound chemists make compounds every day by joining atoms of different elements here we're mixing the element iron and the element sulfur mixing the two elements does not change either one however the chemist knows that heating this mixture will cause the elements to change we call this a chemical change in a chemical change two or more different kinds of atoms join together to form molecules of a new compound we can see that the iron and sulfur are changing we can see that this compound called iron sulfide no longer looks like either the iron or the sulfur that is because the iron and the sulfur underwent a chemical change sometimes chemists use a chemical change to take compounds apart for example this compound is mercuric oxide when it is heated the molecules of mercuric oxide are separated into the element mercury which is forming on the sides of the tube and the element oxygen which we see bubbling in the jar of water remember that matter may be changed chemically in two ways molecules may be separated into atoms as we have seen here or atoms of different elements may be joined together to form molecules as we saw with the iron sulfide in addition to chemical changes matter may also be changed physically breaking glass is a physical change cutting wood is a physical change we can't cut or break water but we can change it physically when water is frozen it changes to ice changing water to ice is a physical change because the ice still has the same composition as the water when the ice melts it physically changes back to water more heating brings about another physical change this time the water changes to steam changing water to steam or ice is a physical change we have learned that matter can be changed physically as well as chemically can you remember some of the other things that we learned about the composition of matter we learned that matter is anything that has weight and occupies space matter is found in three states as a solid as a liquid and as a gas we also learned that all matter may be subdivided into elements like this iron all elements are made up of particles called atoms atoms are the smallest particles that make up an element when atoms of the same element or atoms of two or more different elements join together they form a molecule molecules made of different kinds of atoms form a compound making a compound is one way of changing matter chemically taking a compound apart is another way to change matter chemically you can find examples of chemical changes in matter as you watch your mother cooking food you can find examples of physical changes in the matter that you see and handle every day understanding that all matter is made up of atoms and molecules will help you to answer the question what are things made of