Chemistry

Mixtures

Components of a mixture KEEP their original properties Two or more substances PHYSICALLY combined/ separated NO definite ratio needed (can have as much or as little as you want of each component) Examples: Salt Water Lemonade Salad

A compound has the same properties as the elements that form it. True or False?

False. A compound has different properties from the elements it's formed with.

Elements can be broken down into simpler substances. True or False?

False. An element is a PURE substance that CAN NOT be separated into simpler substances by physical or chemical means/ changes.

Elements can be grouped into 4 categories. True or False?

False. The categories are metals, nonmetals and metalloids. There is only 3.

Compounds can be random combinations of elements. True or False?

False. They are not random combinations. When a compound is formed there is a specific ration to according to the mass of the elements. (Need to equal 8 valence electrons on 2nd or third ring OR 2 valence electrons on the 1st ring)

Compounds are formed and broken down using physical changes. True or False?

False. They can only be broken down through chemical changes.

Mixtures transform into a new substance with new properties. True or False?

False. They have the same properties from the original elements and/or compounds.

Elements

PURE substance CAN'T BE separated or broken down Examples: Sodium (Na) Barium(Ba) Lead (Pb)

Compounds

Pure NEW substance; DIFFERENT properties from the elements that make it Two or more substances CHEMICALLY combined/separated Formed using a SPECIFIC/DEFINITE ratio Examples: Salt(NaCl) Water(H20) Sugar

Elements can be identified using specific properties. True or False?

True. Each element has a unique set of properties that allows you to identify it.

Mixtures can be made with different rations. True or False?

True. You can use different ratios to make mixtues and it will all end up the same. 1tsp of salt + 2 cups of water= salt water but 2tsp salt + 1 cup water= salt water.

Mixtures can be physically separated. True or False?

True. You can use distillation (heating something to separate two different things, salt water uses heat to separate into water and salt), you can just pick it apart (mushroom pizza: just pick off the mushroom if you don't want it). Changes back EASILY.

Molecules definition

a group of atoms bonded together

molecules vs. compounds

molecules is a group of atoms bonded together vs where a compound is a pure substance composed of two or more elements that are chemically changed