Mixtures & Solutions

Investigation 1

Separating Mixtures

Part 1 – Making & Separating Mixtures

Vocabulary• Mixture – a substance containing two or more materials with

different properties.• Property – a characteristic of an object (something you can

observe)– Size, shape, color

• Solution – a special mixture formed when a material dissolves in another.

• Dissolving – a process in which one material disperses uniformly into another material so that the first material seems to disappear.– Two materials mixed evenly together

Part 1 – Making & Separating MixturesMain Ideas/Content• Water and solid material make a mixture.• Some mixtures can be separated by hand or with filters

(ex: M & Ms, coins, water and gravel)• A mixture can be any combination of a solid, liquid, or

gas.– Solid and solid – bronze (copper and tin), steel (carbon and

iron)– Solid and liquid – vegetable soup, cereal & milk– Gas and gas – air– Gas and liquid – soda, seltzer water

Part 2 – Separating a Salt Solution

Vocabulary• Solvent – a substance that dissolves a solute to form a

solution (ex: water).• Solute – a substance that dissolves in a solvent to form a

solution (ex: salt, iced tea crystals, detergent).• Evaporate – to turn into a gas, like water into water vapor.• Element – a substance that cannot be broken down any

further.• Atom – the smallest particle of an element. Atoms are

the building blocks of matter.

Part 2 – Separating a Salt Solution

Main Ideas/Content• A solution is a special kind of mixture in which one

of more materials dissolve in another (ex: salt water).– Solutions can be separated using evaporation

• Almost everything on Earth is a mixture of two or more substances, except for elements.– There are 92 naturally occurring elements on Earth– Elements are arranged on the periodic table from

lightest to heaviest.

Part 3 – Observing Crystals

Vocabulary• Crystal - the solid form of a material that can be

identified by its properties, such as shape, color, and pattern.

• Evaporation – causes liquids to dry up; the liquid turns into gas and disperses into the air.

Part 3 – Observing Crystals

Main Ideas/Content• When a solution evaporates, it leaves the

dissolved solid material behind.• The salt crystal is a square with an X from corner

to corner.• Salt is made up of the elements sodium (Na) and

chlorine (Cl).– A substance made up of more than one element is a

compound.

Part 4 – Separating a Dry Mixture

Main Ideas/Content (FOSS Science Stories – Earth Elements)• Humans are made up of 75% water.• Five elements make up most of the human body (and

most other organisms)– Oxygen, carbon, hydrogen, nitrogen, calcium

• Earth is made up of only a few main elements as well– Iron, oxygen, silicon, magnesium, nickel, sulfur

• Although Earth and everything on it come from only a few elements, those elements combine in a huge variety of ways to create many different materials.

Famous Scientists from Investigation 1

(From FOSS Science Stories)• Humphry Davy – discovered way to separate salt

into sodium and chlorine.• Henry Cavendish – famous for his study of the

composition of air; first person to isolate hydrogen from air.

• Robert Boyle – “father of chemistry”; conducted many experiments with gases.

• Marie Curie –discovered the elements radium and polonium; conducted research on radioactivity; won the Nobel prize twice.