Reaction 3 is the double displacement reaction.
Double displacement reaction occurs when the negatively and the positively charged ions of the compounds interchange their position when the new compound in the product is formed.
<h3>Which is a double displacement reaction?</h3>
In the <u>first reaction</u>, the element lead (Pb) is not an ion and no exchange of the cations or the anions occurs hence it is not a double displacement reaction.
In the <u>second reaction</u>, one compound is getting split into two new compounds and is a decomposition reaction.
In the <u>third reaction</u>, 
in 
and 
in 
are anions and cations and exchanges their places to produce two new compounds 
In the <u>fourth reaction</u>, a single compound is generated as the result of the combination reaction and hence, it is not the double displacement reaction.
Therefore, 
is the double displacement reaction.
Learn more about double displacement reaction here:
brainly.com/question/10091171
When highly electronegative element like oxygen is directly attached to less electronegative element like hydrogen the electrons from less electronegative elements are attracted toward the highly electronegative element, making the less electronegative element deficient in electron density (partial positive) and a partial negative charge on more electronegative element is created. In such situation the intermolecular forces formed are dipole-dipole interactions or hydrogen bond interaction like in HF.
Answer:
Pressure
Explanation:
Apply the definition of pressure to this problem.
Answer:
a
Explanation:
because physical changes are reversible while chemical changes are irreversible
