Atoms and Matter for Kids

rock and learn [Laughter] ah here we are let's review a few things that matter i've learned that matter is anything that has mass and takes up space that's just what i was going to say but there are many other things to learn about matter matter is made up of tiny building blocks called atoms tiny huh are they smaller than a flea or a grain of sand oh much smaller how about a blood cell you can only see under a microscope atoms are even smaller than that each of those things is composed of millions and millions of atoms an atom is the smallest amount of an element you can get that still has the chemical properties of that element scientists have built special tools to look at atoms but even with an electron microscope atoms still look kind of fuzzy so let's look at this model of an atom of helium that's the gas that makes balloons float ah it looks like the tiny atom is made up of even smaller particles that's right the nucleus or center of the atom is made up of protons which have a positive charge and neutrons that don't have any kind of electric charge the number of protons always tells us the type of element this atom is a helium because it has two protons the tiny particles zipping around the outside of the nucleus are called electrons in a real atom they move much faster electrons have a negative charge protons positive neutrons neutral protons positive neutrons neutral and outside the negative electrons reside [Music] protons positive neutrons neutral protons positive neutrons neutral and outside the negative electrons reside so everything around me is made up of atoms does that mean i'm made of kevin adams oh no no no some things like helium oxygen and gold are made up of one kind of atom things made of only one kind of atom are called elements but sometimes different kinds of atoms will bond together to form molecules for example a water molecule is made up of two hydrogen atoms and one oxygen atom oh yeah i've even heard people call water h2o and water is completely different from hydrogen or oxygen by themselves now water like all matter can exist in different states i've learned about states of matter solid liquid and gas that's right and matter can change states under certain conditions let's consider water in its solid form water is called ice but what happens when ice gets too warm to remain as ice it melts oh it changes state from solid to liquid at a certain temperature the temperature at which it changes from solid to liquid is called the melting point now if you heat the liquid water up to its boiling point it will change to its gas state which we call water vapor or steam like in clouds correct each type of matter has its own boiling point and melting point if you have two pieces of the same matter under the same conditions they will have the same melting point and the same boiling point i see [Applause] no not i see i see that reminds me the point at which the liquid water turns to a solid is the freezing point the melting point boiling point and freezing point are only some of the properties of matter physical properties are things you can detect with your senses like when you touch something and it feels cold i touched a doorknob outside on a cold day and it felt really chilly but when i touched the door it didn't feel as cold i'll bet the doorknob was metal and the door was wood you're some kind of mind reader so why did the metal feel colder aren't the doorknob in the door the same temperature yes but metal is a better conductor than wood heat leaves your hand more quickly when you touch the doorknob so the metal feels colder than the wood even though they are the same temperature wood is a better insulator than metal if you had on mittens the metal would not feel as cold because mittens are good insulators too so that's another property of matter and it's called [Music] conductivity are also good conductors of electricity i suppose you'd know about that lumina let's think of some more properties of metals hmm they tend to be shiny especially if you polish them you're talking about luster another fun property of metals is malleability ooh that means that metals can be bent and shaped into important things like wires there are so many more properties of matter color odor density hardness magnetism and texture just to name a few what's this looks like you boys have been making some physical changes huh what do you mean this water boiling is a physical change of matter even though the state changes from liquid to gas the molecules are still h2o still water i get it physical changes don't change the chemical properties of matter like if i break a wooden pencil in half both pieces are still made of wood why don't we think of a different example how about crushing a can or forming metal into wires those are physical changes too but if you really want to mix things up you can make a chemical change take a look at these nails this one is all rusty but how's that different from breaking a stick or crushing a can rust is a chemical change the iron in the nail combines with oxygen in the air to make a new molecule with different properties than iron or oxygen alone and if we burn this paper inside the beaker that will cause a chemical change too the ashes are different from the paper on the molecular level we've made a different kind of matter with a chemical change so far we've learned a lot about pure substances things that are made of a single element or compound like helium it's made of only helium atoms and water is made up completely of h2o molecules but some kinds of matter are combinations of different atoms and molecules we call these things mixtures but wait isn't water just a combination of hydrogen and oxygen atoms how is a mixture any different from that with a mixture you can separate out the parts with a physical change let me show you what i mean suppose we are making a fruit salad i like blueberries strawberries and almonds we can mix those together to make a salad this salad is a mixture i understand what you're getting at you could pull out the almonds if you didn't like those what are you nuts just kidding as i was saying you can separate the salad back into blueberries strawberries and almonds so the salad is a mixture but you can't separate water back into hydrogen and oxygen with a physical change bravo now check this out let's pour salt in this beaker of water [Music] salt and water are each pure substances but they blend together to make a special kind of mixture called a solution in this case the solution is salt water that's a mixture how are you going to take the salt back out with a physical change we'll boil the water remember state changes are physical changes the water evaporates into vapor and leaves the salt behind in the beaker oh that really was a mixture got any more mixtures up your sleeve well i don't have any sleeves but another mixture is right under your nose and in your nose and down in your lungs ah air must be a mixture too smart boy air is a mixture of mostly nitrogen and oxygen some metals are mixtures too we call metal mixtures alloys bronze is an alloy of copper and tin i suppose copper and tin have different melting points that's really bright of you that's how we can separate tin and copper from a bronze alloy just heat it to around 240 degrees centigrade that's hotter than the melting point for tin but way below the melting point for copper we're gonna need a bigger hot plate [Music] you

Channel: Rock 'N Learn

Views: 127,760

Keywords: science for kids, matter for kids, atoms for kids, molecules for kids, chemical changes for kids, mixtures and solutions for kids. Physical Science for kids, 4th Grade Science, 5th Grade Science, Scott Cawthon

Id: CjdeVeu9r9M

Length: 10min 32sec (632 seconds)

Published: Mon Aug 27 2018