Substances and Mixtures

What are the 2 types of pure substances? Elements Compounds

Elements are the simplest substances. Elements CANNOT be separated into simpler substances through any chemical reaction or physical change.

16 If the substance is an element, the smallest particle is an ATOM. What is sulfur’s atomic number? 16 Elements are identified by their atomic numbers. (Number of protons) Sulfur

Name each of the elements on your notes based on the number of protons. magnesium germanium argon chromium terbium lead thorium fermium

Compounds are formed when elements are chemically bonded in a definite ratio. Compounds CAN be separated into simpler substances through chemical reactions.

Covalent compounds are made of MOLECULES. Ionic compounds are made of SALTS which form crystals. Water Sodium Chloride Salt Crystal Water Molecules

Elements will be found on the Periodic Table while compounds will not! How can you tell the difference between elements and compounds if you are told their names? Elements will be found on the Periodic Table of the Elements while compounds will not!

Hint: Only two of the substances are elements. Decide if the substances listed on your notes are elements or compounds. compound element compound compound compound element Hint: Only two of the substances are elements.

Iron and Sulfur mixed together. Mixtures are formed when substance are placed together which will not chemically react. Mixtures CAN be separated based on the physical properties of the substances in the mixture.

There are two main categories of mixtures. Heterogeneous Mixtures Homogeneous Mixtures The substances within the mixture are distinct and easily identified. The substances within the mixture are blended evenly together.

Mixtures are NOT formed with any kind of definite ratio Mixtures are NOT formed with any kind of definite ratio. While brass is a mixture of copper and zinc, there is not an exact recipe and different manufacturers will use a slightly different percentage of each metal. Brass Copper Zinc

While Kool-Aid® is a mixture of sugar, water and flavoring, the amount of sugar can be adjusted to taste. Changing the amount of sugar does not change the identity of the mixture. There is no definite ratio.

Kool-Aid® is sweet because sugar is sweet! Notice that this also shows that substances retain their properties when they are in a mixture! Kool-Aid® is sweet because sugar is sweet! Steel is a mixture of iron and other elements. Steel is magnetic because iron is magnetic. It retains its properties inside the mixture.

Extensive Properties Intensive Properties The physical properties of a substance are the characteristics of a substance that can be used to describe it. There are two types of physical properties: Extensive Properties Intensive Properties Extensive properties are directly related to the size/amount of a sample. Intensive properties are NOT related to the size or amount of a sample.

Fighting crime one extensive property at a time! Remembering this group of Super Heroes can help you remember the extensive properties! MVL MEN The Extender M V L E N ass XXL olume ength oles Captain Extreme nergy Fighting crime one extensive property at a time! umber of particles

While volume, sometimes simply referred to as size and shape, is related to the size of a sample and it can be used to separate a substance from a heterogeneous mixture. If one substance is in larger pieces than the other, the larger substance can be sifted or filtered from the mixture.

Some elements can be separated from heterogeneous mixtures based on the physical property of magnetism. In particular these elements are iron, cobalt, and nickel. Together these elements are known as the Iron Triad.

Distillation is a process that is used to separate a liquid from a homogeneous mixture based on differences in boiling point. 1. Water is evaporated from the solution 2. The evaporated water is cooled and condenses back into a liquid 3. The pure, distilled water is collected. Distillation

Distillation can also be used to separate two liquids which have been dissolved together. Liquids that can be evenly mixed together are known as miscible liquids. Miscible liquids are either both polar or both nonpolar.

Oil and water are immiscible because one is polar and the other in nonpolar. Based on this picture, which liquid is more dense: oil or water? Oil Water

Immiscible liquids can be separated very easily using a device known as a separatory funnel. Notice that this device also separates heterogeneous mixtures based on the property of density.

Solutions Solutions one of the most common forms of mixtures. They are created when substances are evenly mixed together. Solution = Homogeneous Mixture Aqueous solutions are formed with solutes are dissolved in water Alloys are formed when metals are evenly mixed together. Gaseous solutions, like air, formed when gases mix together.

Important Fact: An alloy is made when metals are mixed together. The metals are melted together and mixed. They can be separated by melting the alloy. When a solid has melted completely into a liquid, we say that it is molten. Is melting a physical or chemical change? Melting is a physical change. This means that alloys are NOT a new substance. They are simply a mixture of substances.

(Iron and Nickel Alloy) (Copper and Zinc Alloy) Common Alloys Steel (Iron and Nickel Alloy) Brass (Copper and Zinc Alloy) Bronze (Copper and Tin Alloy)