Mixtures and Elements/Compounds

Question 1

How can mixtures be classified?

Answer 1

By heterogeneous and homogeneous

Question 2

How can mixtures be separated?

Answer 2

Filtration and Distillation

Question 3

Mixture

Answer 3

Physical blend of two or more components(parts)
Classification is based on the distribution of these components

Question 4

Heterogeneous Mixture

Answer 4

A mixture in which the composition is not uniform throughout
Ex: chicken soup, oil & vinegar, soil

Question 5

Homogeneous mixture

Answer 5

A mixture in which the composition is uniform throughout also known as a solution
-Solutions can help solids, liquids, or gasses
Ex:Stainless steel, motor oil, and air

Question 6

Phase

Answer 6

Any part of a sample with uniform composition and properties
-A homogeneous mixture has only a single phase
-A heterogeneous mixture will have two or more phases, often seen as layers in liquids

Question 7

Separation of mixtures

Answer 7

Differences in physical properties can be used to separate materials

Question 8

Filtration

Answer 8

The process that separates a solid from a liquid in heterogeneous micture
Ex:Colander/sopa strainer or filter paper

Question 9

Distillation

Answer 9

A process used to separate dissolved solids from a liquid, which is boiled to produce a vapor that is then condensed into a liquid

Question 10

How are elements and compounds different

Answer 10

Elements are pure substances
Compounds are substances

Question 11

How can substance and mixtures be distinguished

Answer 11

If particles are the same it is a pure substances and if there is more than one particle its a mixture

Question 12

What do chemists use to represent elements and compounds?

Answer 12

Chemical symbols are to represent elements and chemical formulas are used to represent compounds

Question 13

Distinguishing Elements

Answer 13

-the simplest pure substances
-made up of ONLY one type of atom
-can NOT be broken down to smaller substances by ordinary means
-Approximately 100 known elements in nature

Question 14

Distinguishing compounds

Answer 14

-two or more elements combined through a chemical reaction
-composed of definite group of molecules or ions that are chemically bonded
-Also a pure substance-definite composition

Question 15

Chemical change

Answer 15

A change that produces matter with a different composition than the original matter

Question 16

Chemical change Examples

Answer 16

Heating is one process that produces a chemical change
Example:Heating table sugar goes through a chemical change produce solid carbon and water vapor

Question 17

Properties of Compounds

Answer 17

Important: The set of chemical and physical properties of a compound differ from those of elements that make up the compound
Example: The properties of water (liquid) are different from the properties of oxygen (gas) and hydrogen(gas)

Question 18

Distinguishing Substances and Mixtures

Answer 18

If the composition of a material is fixed(homogeneous) the material is a substance
If the composition varies, the material is a mixture of

Question 19

Chemical Symbols used for?

Answer 19

Chemists use chemical symbols to represent elements

Question 20

Chemical symbol

Answer 20

A one-or two-letter representation of an element. The first letter is ALWAYS capitalized
Examples:Hydrogen(H) Oxygen(O) Carbon(C) Gold(Au)

Question 21

Chemical Formulas

Answer 21

Are used to represent compounds
- If there is a number of subscript in the formula, it designates how many atoms of each element are present

Question 22

Subscript

Answer 22

A subscript is the small number at the bottom of the letter. For example the 2 in H2O

Exception: if there is only 1 atom then the subscript is omitted. For example, there is only one Oxygen atom in H2O so there is NO number on the O