Matter and Atomic StructureSection 3.2- How Atoms Combine

VocabularyCompound

Substance composed of atoms of two or more different elements that are chemically combined.

Exp. Water molecule (hydrogen & oxygen)

Exp. Table salt (chlorine – poisonous & sodium –

toxic)

VocabularyChemical bond

Force that hold the atoms of elements together in a compound.

COMPOUNDS

Most compounds on earth are held together by 2 types of bonds:1.Covalent bonds2.Ionic bonds

VocabularyCovalent bond

Two atoms combine with each other by sharing electrons.

C=caring=sharing Exp. Water molecule 2 Hydrogen share

Electrons with 1 oxygen

VocabularyIon

An atom that gains or loses and electron is a charge particle.

Ionic bond The attractive force between to ions of

opposite charge. Example Table salt (NaCl) One of the most common compounds on

Earth magnesium oxide (MgO). Compounds formed by ionic bonding

are known as ionic compound.

Covalent bond vs. Ionic bond

Ions

Atoms gain/loose electron from their outermost energy levels.

Anion-When an atom gains an e-, it becomes more negative.

Cation-When an atom looses an e-, it becomes less negative and more positive.

VocabularyChemical Reaction

Change of one or more substances into other substances.

Chemical ReactionExample- Formation of water

H2O

Example- Formation of Rust

Fe2O3

Chemical Reaction

Example- PhotosynthesisLight energy + carbon dioxide + water = glucose + oxygen

Q + 6CO2 + 6H2O = C6H12O6 + 6O2

Chemical Reaction

MixtureA mixture is a combination of two or more

components that retain their identity.

SolutionsA homogeneous mixture is called a solution.

Solid solution-Metal alloys:Bronze; mixture of Copper (Cu) and Tin (Sn)

atoms,Brass; mixture of Copper (Cu) and Zinc (Zn)Liquid solution:Magma – molten rock/lavaGaseous solution:Atmosphere/Air

VocabularyAcid

Substance that produces (H+) hydrogen ions in water.

Most common in our environment -carbonic acid

Responsible for the dissolution of limestone; forming caves.

VocabularyBase

Substance that produces (OH+) hydroxide ions in water.

A base can neutralize an acid.