Resumen Quimica En Ingles

Chemistry Review
http://www.bbc.co.uk/schools/ks3bitesize/science/chemistry/

C1 – The Elements of Chemistry

Definitions:
1. Atom: It is the smallest part of an element that can exist on its own
2. Element: It is a substance consisting in only one type of atom
3. Compound: It contains two or more elements that are chemically combined and therefore cannot be easily separated usingphysical methods
4. Molecule: It is the smallest unit of a substance that can exist alone and retain the character of that substance
5. Mixture: It is formed when two or more substances are mixed, but not chemically combined. Therefore it can be easily separated using physical methods
6. Atomic Mass (Mass Number, Nucleon Number): It is the number of protons and neutrons inside the atom’s nucleus7. Atomic Number: It is the number of protons in the nucleus of an atom
8. Nucleon Number: It is the number

Differences between mixture and compound:
|Mixture |Compound |
|Components are not chemically combined |Components are chemically combined|
|Components are present in any proportion |Components combine in a fixed proportion |
|Components can be separated easily by physical methods (filter,|Components cannot be separated easily by physical methods |
|boil, etc.) ||
|Heat / light not given off on mixing |Heat / light often given off when a compound is formed |
|Examples: sand and water, salt and water, air |Examples: water, carbon dioxide |

Table of Properties:
|Property |Solid |Liquid|Gas |
|Distance between particles |Close together |Close together |Far a part |
|Forces between particles |Strong |Fairly Strong |Weak |
|Shape|Fixed |Not Fixed |Not Fixed |
|Volume |Fixed |Fixed |Not Fixed |
|Movement of particles |Cannot Move (Vibrate only) |Can move|Move Freely |
|Arrangement of particles |Regular |Not so Regular |Random |
|Diagram |[pic] |[pic] |[pic] |
|Examples |Rock, book,table |Water, ethanol, mercury |Helium, hydrogen, oxygen. |

The Kinetic Theory:
1. At any temperature, particles are moving
2. At higher temperature, particles gain energy and move faster

Changes in Matter:

Example: A solid that can sublime is:
Dry ice (solid carbon dioxide)
Naphthalene (moth balls)
Rodine

Kinetic Theoryand Changes in Matter:
1. When a solid is heated, its particles (atoms and molecules) vibrate more. Eventually they gain enough energy to break the bonds holding them together. The solid melts into a liquid
2. If a liquid is heated, the particles gain energy and move about more. Finally they get energy to move completely away from each other. Liquid evaporates into a gas.’

The Atom:
|...