chapter 6 and 7 test review

Chapter 6+7 Test Review

A Table Of Elements:

- Element Symbol: Abbreviation of a chemical element - Ag= argentum

- All elements are pure substances

Properties of Metals and Non- Metals;

Non- Metals: Usually a gas or dull-powdery solid, do not conduct heat or electricity

Metals: lustrous, malleable, and ductile, conduct heat and electricity

Metalloids: Have both metal and non-metal properties

Groups of The Periodic Table:

•Organizes elements into periods (rows) and groups (columns)

• Group 1: Alkali, they're soft, shiny, sivery, and highly reactive metais

•Croup 2: Alkine earth metals, light, shiny, and silvery, not as soft or reactive as alkali metals

•Croup 17: Halogens, very reactive, rarely found in element form, often form compound w/ alkali metals.

•Group 18: Noble Gases, very stable and rarely react with other chemicals

Putting Atoms Together:

•Atoms consist of a nucleus, inside the nucleus is protons and neutrons, electrons Float around the outside

• Isotopes: Atoms with the same amount of protons but different number of neutrons

Mass Number, Atomic Number, Atomic Mass:

the mass of an atom consists of the nucleus, neutrons and protons.

• mass number help scientists distinguish between the isotopes of an element

• Atomic number is the amount of protons each element contains

• Atomic mass is the mass of an atom and is measured in Atomic Mass Unit (U)

Rutting Atoms Together;

• A molecule is to or more atoms of the same or different elements that are chemically joined

• Examples of Molecules: Air is 80% nitrogen molecules, 20% oxygen molecules and small amounts of water and carbon dioxide molecules

Chemical Formula:

• A chemical formula is the notation used to indicate the type and number of atoms in a pure substance

•The subscript indicates the number of atoms of the element preceding it: O2, H3

Molecular Compounds:

•A molecular element is a molecule consisting of atoms of the same element

• Diatomic molecules are molecules consisting of two atoms of the same substance

•There's 7 diatomic molecules: H2, N2,02, F2, Cl2,Br2,I2

• A molecular compound is a molecule that consists of two or more different elements

A molecular compound is between a non-metal and non- metal

Ionic Compounds:

• When metal and non-metal atoms combine, they form ionic compounds which have negatively or positively charged particles called ions

• Metals always lose electrons and become cations

•Cations: positively charged ion (loses electrons)

Non- metals gain electrons and become anions

• Anions: negatively charged ions (gained electrons)

•Cations and anions attract each other because they have opposite charges

Atoms Combining:

• Atoms combine to become more stable - elements that do not have the maximum number of electrons in their outer shell combine with other elements to obtain this maximum number of electrons

•Atoms become more stable by gaining, losing, or sharing electrons

Ionic Compounds (continued):

•Name ionic compounds by writing the metal first, then the non-metal ending in ide

Molecular Compound -Non-metals and Non-Metals;

•When two nonmetals combine they neither gain or lose electrons, instead they share erections, which creates a bond that holds them together

• This bond is called a covenant bond

•The bonded atoms form a molecule.

Difference between ions and atoms:

-ions are charged atoms that have either gained or lost electrons

-atoms have the same amount of protons and electrons