Answer:
Option 4) equal to
Explanation
When having a reversible reaction, this reaction (or system) reaches the balnace, it is observed that relative quantitives for all compounds (this is, reactives and products), remain constant
The species concentration does not change over time, and; in the same way; there are no physical changes as time goes by
For example, for the following reaction :
aA + bB ⇔ cC + dD
Compounds A and B react to give products C and D. The two way arrows means that this systme has reached the balance (is in equilibrium)
Two parts are stage and coarse focus
Because it is toxic to humans if absorbed or consumed.
Mass and number of atoms always stay the same