Mixtures and Solutions
K12 Handhelds
6th Grade Informational and Literature Reading Texts
Matter is the stuff all around us. Matter takes up space and has weight and mass. mass is the amount of Matter there is. It is often measured in grams. Matter has properties. properties are things you can notice or observe about something. Some properties are size, color, smell, texture, and shape. There are three states that Matter can exist in, solid, liquid & gas.
Solids have a fixed shape. They don't change shape if you put them in different containers. Examples of a solid are a desk, a brick, paper, or coal. Water that is in a solid state is ice.
liquid has no fixed shape. Liquids do have a fixed volume or amount of space they take up. If you have one cup of milk, it is the same amount of milk whether it is in a small cup or a large bucket. Liquids change shape depending on what container they are in. Examples of liquids are milk, juice, and gasoline. When water comes out of the faucet, it is in the liquid state.
A gas has no fixed shape or volume. A gas can shrink or grow to fill whatever container it is in. Examples of gas are the air we breathe, helium, and smoke. Water changes into steam when it is heated. Steam is a gas.
All three states of Matter have weight. Even a gas has some weight.
When two or more kinds of Matter are put together, the result is a mixture. Examples of mixtures include:
trail mix (mixture of peanuts, raisins, and chocolate candy)
dirt (mixture of minerals, small rocks, sand, and other materials)
ocean water (mixture of salt and water)
air (mixture of gases, including oxygen, carbon dioxide, and nitrogen)
One important thing about a mixture is that it can be separated back into its separate parts. Sometimes this is easy. For example, you can sort trail mix into peanuts, raisins, and chocolate candy.
Special tools can be used to separate mixtures. A screen with holes in it can be used. If you use a screen to separate gravel, the small dust and pebbles will fall through. The larger pieces of rock will not fall through. Another tool is a filter. Filter paper has very small holes in it that you can't even see. liquid will go through filter paper, but small solid pieces will not go through.
One special kind of mixture is a solution. A solution is when things are mixed together completely evenly. You can't see or tell the difference between one part and another. Scientists call this a homogeneous mixture. That means that they are the same throughout. There are no large pieces of one of the parts.
Solutions cannot be separated by a screen or a filter. That is because the parts are mixed together in a way that they all have the same size.
One example of a solution is when a solid is dissolved into a liquid. When something dissolves, it spreads evenly throughout and seems to disappear. When you stir sugar into water and it seems to disappear, it has dissolved. You can't see the salt in ocean water because it is dissolved.
As we saw above, a solution can be separated into its parts just like other mixtures. This happens through evaporation. When something evaporates, the liquid part changes to a gas and goes away, leaving just the solid behind. If you leave a pan of sugar water out in the sun, the water will evaporate, leaving behind just the solid sugar. Some Solids, like salt and sugar, form crystals. Crystals are a kind of solid that are clear and are organized in repeating patterns. Examples of crystals are diamonds, quartz, salt, and sugar.
Whenever you separate a mixture or a solution, there will always be the same amount of each part as there was before they were mixed. This is called conservation of Matter. Imagine that you mix 2 grams of sugar into 1 liter of water. If you evaporate the water, there will be 2 grams of sugar left. There will also be 1 liter of water, but it will be in the air in the form of a gas.
In this kind of solution, the liquid is called the solvent. The solid, like the salt or sugar, is called the solute.
Solids have a fixed shape. They don't change shape if you put them in different containers. Examples of a solid are a desk, a brick, paper, or coal. Water that is in a solid state is ice.
liquid has no fixed shape. Liquids do have a fixed volume or amount of space they take up. If you have one cup of milk, it is the same amount of milk whether it is in a small cup or a large bucket. Liquids change shape depending on what container they are in. Examples of liquids are milk, juice, and gasoline. When water comes out of the faucet, it is in the liquid state.
A gas has no fixed shape or volume. A gas can shrink or grow to fill whatever container it is in. Examples of gas are the air we breathe, helium, and smoke. Water changes into steam when it is heated. Steam is a gas.
All three states of Matter have weight. Even a gas has some weight.
When two or more kinds of Matter are put together, the result is a mixture. Examples of mixtures include:
trail mix (mixture of peanuts, raisins, and chocolate candy)
dirt (mixture of minerals, small rocks, sand, and other materials)
ocean water (mixture of salt and water)
air (mixture of gases, including oxygen, carbon dioxide, and nitrogen)
One important thing about a mixture is that it can be separated back into its separate parts. Sometimes this is easy. For example, you can sort trail mix into peanuts, raisins, and chocolate candy.
Special tools can be used to separate mixtures. A screen with holes in it can be used. If you use a screen to separate gravel, the small dust and pebbles will fall through. The larger pieces of rock will not fall through. Another tool is a filter. Filter paper has very small holes in it that you can't even see. liquid will go through filter paper, but small solid pieces will not go through.
One special kind of mixture is a solution. A solution is when things are mixed together completely evenly. You can't see or tell the difference between one part and another. Scientists call this a homogeneous mixture. That means that they are the same throughout. There are no large pieces of one of the parts.
Solutions cannot be separated by a screen or a filter. That is because the parts are mixed together in a way that they all have the same size.
One example of a solution is when a solid is dissolved into a liquid. When something dissolves, it spreads evenly throughout and seems to disappear. When you stir sugar into water and it seems to disappear, it has dissolved. You can't see the salt in ocean water because it is dissolved.
As we saw above, a solution can be separated into its parts just like other mixtures. This happens through evaporation. When something evaporates, the liquid part changes to a gas and goes away, leaving just the solid behind. If you leave a pan of sugar water out in the sun, the water will evaporate, leaving behind just the solid sugar. Some Solids, like salt and sugar, form crystals. Crystals are a kind of solid that are clear and are organized in repeating patterns. Examples of crystals are diamonds, quartz, salt, and sugar.
Whenever you separate a mixture or a solution, there will always be the same amount of each part as there was before they were mixed. This is called conservation of Matter. Imagine that you mix 2 grams of sugar into 1 liter of water. If you evaporate the water, there will be 2 grams of sugar left. There will also be 1 liter of water, but it will be in the air in the form of a gas.
In this kind of solution, the liquid is called the solvent. The solid, like the salt or sugar, is called the solute.