I believe the correct answer from the choices listed above is the second option. The type of change and the explanation for the change in calcium carbonate would be that it is a <span>physical change </span>because even though a particle size change was observed, the calcium carbonate retained its original properties and was not transformed into a new substance.
Answer: BF3
Explanation: boron needs 4 electron to obtain octet and Fluorine has just one. For the valence shell to be completely filled it will have to form BF4- with 4 fluorine atom surrounding it.
The correct answer is the second answer choice: bringing iron in!
Different between potential energy and mechanical energy
In terms of grammar, “reduce the acidity of the solution.”