Metals

Around 75% of the elements in the periodic table are metals. Metals are known for conducting electricity and heat well. Many metals are strong, shiny, and hard. They are also often malleable, meaning they can be shaped without breaking or cracking. 

Types of Metals 

There are all sorts of metals. The periodic table lists the metals that are pure elements. Meaning they are all made out of the same atom. These metals include many elements that you are probably already familiar with like iron, gold, silver, and platinum. There are other elements like sodium and potassium that you may not usually think of as metals. 

The periodic table divides up metal elements into different types including alkali metals, alkaline earth metals, and transition metals, just to name a few. 

Alloys 

Many metals that we use today are alloys. Alloys are metals that combine two or more elements. They could also be called metallic compounds. Often alloys are stronger and harder than pure metal. 

Steel is a very strong type of alloy. There are a variety of steel alloys. A common one is made out of iron combined with small amounts of carbon. Stainless steel that we use for utensils and kitchen appliances is steel with chromium. Steel is used in much of the world's industries. 

Aluminum alloys are also very important. Aluminum is one of the most plentiful elements on earth. When combined with other elements like copper and silicon, it can make a strong, but light alloy. It also doesn't rust like many metals. Aluminum is used in making all sorts of items like airplanes, soda cans, ladders, and golf clubs. 

Aluminum

Bronze was one of the first alloys used to make tools. Bronze is a combination of copper and tin. 

Mining and Making Metal 

Metal is found inside of rocks in mines. These rocks are called ore. In order to separate the other minerals in the rock from the metal, the ore is heated to really hot temperatures in a process called smelting. 

Metal Ore

Recycling 

Since the mining of metals is bad for the environment and expensive, we need to recycle the metals we have used once we are done with them. This can save on energy, cost, and help the environment. As an example, it takes only 5% of the energy to recycle an aluminum can than it takes to mine the same amount of aluminum from the ground. 

Fun Facts about Metals

• Silver conducts electricity better than any other metal.
• Brass is an alloy made from zinc and copper.
• Pure gold is too soft for many things so most gold is combined with other metals to make it stronger. 24 karat gold is 100% pure gold. Much jewelry is made from 18 karat gold which is 75% gold and 25% other metals.
• World time periods are often listed by the metal used. History before metal was used is called the Stone Age. Next was the Bronze Age, followed by the Iron Age.
• The science of studying metals is called metallurgy.

Crystals

Crystals

What are crystals? 

Crystals are a special kind of solid material where the molecules fit together in a repeating pattern. This pattern causes the material to form all sorts of unique shapes. 

Amethyst Crystal

How do they form? 

The process of crystal forming is called crystallization. Crystals often form in nature when liquids cool and start to harden. Certain molecules in the liquid gather together as they attempt to become stable. They do this in a uniform and repeating pattern that forms the crystal. 

In nature, crystals can form when liquid rock, called magma, cools. If it cools slowly, then crystals may form. Many valuable crystals such as diamonds, rubies, and emeralds form this way. 

Another way crystals form is when water evaporates from a mixture. Salt crystals often form as salt water evaporates. 

What unique properties do crystals have? 

Crystals can have very flat surfaces called facets. They can form geometric shapes such as triangles, rectangles, and squares. The shapes are a direct result of the type of molecules and atoms that make up the crystal. Smaller crystals and larger crystals that were formed of the same molecules and in the same method should have similar shapes. 

There are seven basic crystal shapes, also called lattices. They are Cubic, Trigonal, Triclinic, Orthorhombic, Hexagonal, Tetragonal, and Monoclinic. 

Interesting Types of Crystals 

Snowflakes - Snowflakes are ice crystals that are formed high in the clouds when water freezes. They always have six sides or arms, but every one of them is unique. 

Timing crystals - When an electric current is sent through some crystals they vibrate at a very precise frequency. Quartz crystals are used in watches and other electronics to keep an accurate time. 

Quartz - Quartz is a common mineral and crystal. It is one of the hardest common minerals. The gemstone amethyst is a purple type of quartz. 

Diamonds - Diamonds are one of the most valuable minerals on Earth. Not only for jewelry, but diamond is also the hardest substance on earth and is used for special tools such as diamond saws. Diamond is a form of the element carbon. 
Fun facts About Crystals

• Crystallography is the science of studying crystals and how they form.
• Some crystals, like diamonds, are really just one giant molecule made from lots of atoms of a single element.
• A lot of computer screens use liquid crystals for their display.
• They are very popular in jewelry because they can sparkle and come in many different colors.
• Some living organisms are able to produce crystals.

Acids and Bases

Acids and Bases

Acids and bases are two special kinds of chemicals. Almost all liquids are either acids or bases to some degree. Whether a liquid is an acid or base depends on the type of ions in it. If it has a lot of hydrogen ions, then it is an acid. If it has a lot of hydroxide ions, then it is a base. 

pH Scale 

Scientists use something called a pH scale to measure how acidic or basic a liquid is. pH is a number from 0 to 14. From 0 to 7 are acids, with 0 being the strongest. From 7 to 14 are bases with 14 being the strongest base. If a liquid has a pH of 7, it's neutral. This would be something like distilled water. 

Strong Acids and Bases 

Acids with a low pH of around 1 are very reactive and can be dangerous. The same is true for bases of a pH near 13. Chemists use strong acids and bases to get chemical reactions in the lab. Although they can be dangerous, these strong chemicals can also be helpful to us. 

*** Never handle acids or bases in a chemistry lab unless supervised by your teacher. They can be very dangerous and can burn your skin.

Acids and Bases in Nature 

There are many strong acids and bases in nature. Some of them are dangerous and used as poisons by insects and animals. Some are helpful. Many plants have acids and bases in their leaves, seeds, or even their sap. Citrus fruits like lemons and oranges have citric acid in their juice. This is what makes lemons taste so sour. 

Acids and Bases in our Bodies 

Our bodies use acids and bases too. Our stomachs use hydrochloric acid to help digest foods. This strong acid also kills bacteria and helps to keep us from getting sick. Our muscles produce lactic acid when we exercise. Also, our pancreas uses a base called an alkali to help with digestion. These are just a few examples of how the chemistry of bases and acids help our bodies function. 

Other Uses 

Science and technology makes good use of acids and bases. Car batteries use a strong acid called sulphuric acid. Chemical reactions between the acid and lead plates in the battery help make electricity to start the car. They are also used in many household cleaning products, baking soda, and to make fertilizer for crops. 

Fun Facts

• Acids and bases can help neutralize each other.
• Acids turn litmus paper red, bases turn it blue.
• Strong bases can be slippery and slimy feeling.
• Acids taste sour, bases taste bitter.
• Proteins are made up of amino acids.
• Vitamin C is also an acid called ascorbic acid.
• Ammonia is a base chemical.