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Mixtures

  • Science
  • Grades 3-4
  • 190 words
  • Also written for younger readers

In chemistry, a mixture is a substance that is made up of two or more simpler substances. These substances can be chemical elements or compounds. A mixture can be made of liquids, solids, or gases.

Characteristics

A mixture is not the same as a compound which is made of two or more atoms connected together. For instance, a mixture of the gases hydrogen and nitrogen contains hydrogen and nitrogen, not the compound ammonia which is made of hydrogen and nitrogen atoms.

A mixture where the different parts can be distinguished easily is called heterogenous, one where this is not the case is called homogeneous. A third form is called colloid.

If one substance in a mixture dissolves in the other, it is called a solution. For example, if sugar is put in water it forms a mixture, then dissolves to make a solution. If it does not dissolve, it would be called a suspension.

Solids can be mixtures also. Alloy s are mixtures. Many kinds of soil and rock are mixtures of different minerals. Thus, a mixture is made of two or more elements and/or compounds which are not chemically combined.

Written for younger readers

Mixtures, in simpler words

This version comes from Wikijunior, a set of books written for children aged 8 to 11. It is shorter and uses plainer language than the article above.

From Wikijunior: The Elements

=Mixtures II= There are a few more words you might hear when people talk about mixtures. We can’t cover all of them, but we’ll give you a quick overview of the important mixtures.

Alloys are basically a mixture of two or more metals. Don’t forget that there are many elements on the periodic table. Elements like calcium and potassium are considered metals. Of course, there are also metals like silver and gold. You can also have alloys that include small amounts of non-metallic elements like carbon. Metals are the key thing to remember for alloys.

The main idea with alloys is that they are better at something than any of the metals could be alone. Metallurgists (people who work with metals) sometimes add chromium and/or nickel to steel. While steel is already an alloy that is a very strong metal, the addition of small amounts of the other metals help steel resist rusting. Depending on what element is added, you could create Stainless Steel or Galvanized Steel. It’s always about improving specific qualities of the original. Another good example of an alloy happens when metallurgists add carbon to steel. A tiny amount of carbon (a non-metallic element) makes steel stronger. These special carbon-steel alloys are used in armor plating and weapons.

Amalgams are a special type of alloy. Anyway, amalgams are alloys that combine mercury and other metals in the periodic table. You might know mercury as “quicksilver” or the metal that is liquid at room temperature. The most obvious place you may have seen amalgams is in old dental work. The fillings in the mouths of your grandparents may have been amalgams. We already talked about mercury’s being a liquid at room temperature. That physical trait was used when they made fillings. Let’s say you have an amalgam of mercury and silver. When it is created, it is very soft. As time passes, the mercury leaves the amalgam and the silver remains. The silver that is left is very hard. Voila! You have a filling!

NOTE: Never, ever, play with mercury! It is very poisonous. You shouldn’t even touch it because it will seep into your skin. Dentists don’t usually use amalgams with mercury anymore because it may have slowly poisoned people and gotten them sick.

These special colloids (another type of mixture) have a mixture of oils and waters. Think about a botttle of salad dressing. Before you mix it, there are two separate layers of liquids. When you shake the bottle, you create an emulsion. As time passes, the oil and water will separate to their original states.

Where this page comes from

The article above is adapted from “Mixtures” on Simple English Wikipedia, by its contributors. We removed reference markers, navigation boxes and tables, expanded measurement templates into readable numbers, and kept the prose otherwise intact. The simpler version is adapted from Wikijunior on Wikibooks.

Both sources are published under CC BY-SA 4.0, so this page is published under the same licence. You may share and adapt it, including commercially, as long as you credit the original and keep the same licence.

Worksheets, answer keys and printable layouts elsewhere on K5Print are our own work and are not covered by this licence.