Unit 6. Chemical reactions

Transformations in matter that affect its nature. New substances are formed

(a)  

When particles collide with enough energy and appropriate orientation (right direction) in a chemical reaction, the collition is:

• Imminent

• Sufficient

• Efficient

• Inefficient

Substances that react:

(a)  

Sunstances that are obtained in a chemical reaction:

• Reactants

• Compounds

• Products

• Molecules

Substances that are added to a reaction to increase its speed:

(a)  

Factors that affect the speed of a chemical reaction:

• Temperature, concentration of products, particle size, Catalysts.

• Catalysts, concentration of reactants, particle size, temperature.

• Catalysts, reactants, particle concentration, temperature.

• Temperature, particle size, Size of products, concentration.

In a chemical reaction, matter is neither created, nor destroyed. It is only transformed.

(a)  

Number that indicates the proportion in which a substance is involved in a chemical reaction:

• Coefficient of reaction

• atoms number coefficient

• Stoichiometric element

• Stoichiometric coefficient.

In a chemical reaction, on the right of each formula, we write its:

(a)  

In a chemical reaction, the number of atoms of each element must be the same before and after the reaction. Once we achieve this, we say that the reaction is:

(a)