Chemical Reactions and equations

representing chemical equations

1) model

2) words
3) chemical

a chemical reactions

is a process in which one or more substances are converted to one or more different substances

during a chemical reaction

chemical bonds break between atoms in the reactants and form new bonds in the products - the atoms rearrange t form new bonds - position of electrons change = products with different properties to reactants

signs that indicate chemical reaction

indicators of a chemical reaction

essential characters for the occurrence of a chemical reaction

breaking and formation of bonds

characteristics of a chemical reaction

1. change in color

2. formation of a precipitate

3. formation of a gas

4. odour change

5. temp change

5 main types of reactions

1. synthesis reaction ( combination reaction)

2. decomposition reaction

3. single displacement reaction

4. double displacement reaction

5. combustion reaction

synthetics reaction / combination reaction definition

two or more substances combine to form one product

synthetics reaction / combination reaction general form

A+B→ A+B

decomposition reaction definition

one compound breaks down into simpler substances

decomposition reaction general form

AB→A+B

single displacement reaction definition

one element replaces another in a compound

single displacement reaction general form

A+BC→AC+B

double displacement reaction definition

two compounds switch components to form two new compoiunds

double displacement reaction general form

AB+CD→AD+CB

combustion reaction definition

a substance reacts with oxygen, releasing heat and light

combustion reaction general form

Fuel +O2→ CO2+H20

reactants

reagents

Law of Conservation of Mass

mass can neither be created nor destroyed

total mass of reactants =

= total mass of products

ionic bonds have strong bonds and

high melting points

postive proton ____ postive proton

repels

chemical beahviour of an element is determined by

the number and arrangement of electrons

CO

carbon monoxide

Helium valence electrons

2

nitrogen gas (N2) is a

element