Science weekly exam

At the begining it was tought that the oxidation occured when _______ was involved.

• oxigen

• oxidation

• reduction

• chemical reactions

It is a process involving the electron transfer from an atom to another one.

• Reduction

• Oxidation

• Loss of electrons

• Redox Reactions

In a Redox reaction the oxidation number is attributed to the:

• participant ions

• all ions on the periodic table

• participant atoms

• all atoms on the periodic table

When the oxidation occurs there is a :

• loss of atoms

• gain of atoms

• loss of electrons

• gain of electrons

When the reduction occurs there is a :

• atom gain

• atom loss

• electron gain

• electron loss

How are we going to write the oxidation number

• 2+

• +2

• -/+2

• 2-/+

In this picture which is the element that gets oxidized?

• Zn

• Cu

In this picture which element gets reduced?

• Cu

• Mg

Oxigen has an axidation number of -2 except in:

• peroxides

• hydrides

• polyatomic ions

• neutral substances

These two options are a great example of redox reaxtions:

• corrosion

• combustion

• paraffin

• butane