Chemistry Building Science Champions

Properties of Matter Hard or soft Rough or smooth Round or square Hot or cold Able to catch fire Any color or no color Each specific substance has its own combination of properties that can be used to identify the substance.

Elements Element- a substance that cannot be broken down into any other substances by chemical or physical means. Elements are the building blocks of matter because all matter is composed of elements. Each element is made up of tiny particles called ATOMS. Each element has its own Symbol. The first letter is always capitalized and the second letter is lower case. ***Some elements only have 1 letter.

Elements Elements’ symbols are based off their Latin roots.

Compounds Compound is a substance made of 2 or more elements chemically combined in a specific ratio. A formula shows the ratio of elements in the compound. H 2 0 CO 2 The subscript refers to how many elements of the letter before the subscript. 2 hydrogen in H 2 0 and 2 Oxygen in CO 2

Mixture Mixture is made from 2 or more substances – elements, compounds or both – that are together in the same place but are not chemically combined into a new substance.

Mixture vs. Compound Mixture Substances keep their individual properties. The parts of a mixture do not have to be in exact ratios. Salt water Compound Substances combined to form new properties. Elements in a compound have to be exact. H 2 0

Change in Matter Physical Change A physical change alters the form or appearance of material but does not make the material a new substance. Example – new color or shape. Matter has 3 principle states: Solid, Liquid and Gas. Chemical Change Chemical change or chemical reactions produce new substances. Same elements as original substance but rearranged into a new combination.

Atoms + Molecules Atoms Atoms are usually linked with one or more atoms. The force that holds atoms together is called a chemical bond. Molecule A combination of two or more atoms that are bonded together is called a molecule. Molecules can be made of the same type of atom or different types.

Periodic Table of Elements

Elements from Earth There are 92 naturally occurring elements on Earth. How is there roughly 117 elements on the Periodic Table of Elements if only 92 are natural? How and who makes them?

Review Matter has many properties. There are 92 elements found in nature. Each is represented by a symbol. An atom is the smallest part of an element. A compound is made when 2 or more elements combined with one another. A mixture is made of 2 or more substances. Matter can be changed 2 ways – either physical or chemical.

States of Matter Solid – ice cube Liquid – water Gas – Steam

Solid Solid- has definite volume and definite shape. A desk in the classroom has definite volume and shape. The particles in a solid are packed tightly together and stay in fixed positions

Solids continued Crystalline Solid – solids that are made of crystals – ie. Salt, snow, sand Melting Point – the temperature at which crystalline solids melt. Amorphous Solids – solids not arranged in a particular pattern – ie. Rubber, wood, plastic

Liquid Liquid – has no shape, takes the shape of a container. Liquids easily flow. Water pouring out of a water bottle. Viscosity – the resistance of a liquid to flow. Water pouring out a water bottle has little or low viscosity. Honey poring out of a jar has a lot of viscosity or high viscosity. Flows slowly

Liquids Continued The particles in a liquid are easily moved and flow about the container freely

Gas Gas - can change volume easily. Takes on the shape of a container Gas particles fill the area that is available to them. Gas particles spread apart very easily

Review There 3 states of matter – solid, liquid and gas. In each state the particles are arranged differently. Each state has unique properties.