Answer:
Combining the two clear colorless liquids is a chemical change.
Explanation:
Because a different solid substance is formed. Tell students that a precipitate is an insoluble solid that forms when two solutions are combined and react chemically. Insoluble means that the solid will not dissolve.
what??? i need more information
Yes if you add an energy to an electron the electron will become excited, and it will jump to its highest level then go back down releasing energy
Isotopes are atoms of the same element that have different numbers of neutrons.
<u>Answer:</u>
<u>For 1:</u> Neutralization reaction
<u>For 2: </u>Zinc is more reactive than lead and less reactive than calcium.
<u>Explanation:</u>
When a base reacts with an acid to form a salt and water molecule, it is known as a neutralization reaction. The general equation follows:

The chemical equation for the reaction of calcium hydroxide and nitric acid follows:

A single displacement reaction is defined as the reaction in which a more reactive metal displaces a less reactive metal from its salt solution. The general chemical equation follows:

where,
Metal A is more reactive than metal B
The reactivity of metals is judged by the reactivity series where a metal lying above in the series is more reactive than the metal lying below it.
From the reactivity series below,
Zinc lies above in the series than lead thus is more reactive and will easily replace lead from its aqueous solution.
While zinc lies below in the series than calcium thus is less reactive and will not easily replace calcium from its aqueous solution.

