Answer:
B is a precipitation reaction.
Explanation:
This is because a precipitation reaction is when a solid is made from the combination of cations and anions in a solution to create a solid.
A law is statement about an observed concept. A theory involves the explanation of scientific concepts or principles. A hypothesis is the predicted explanation about some concepts that has to be tested in order to prove it to be right. An observation is the observing the results of a scientific experiment carried out to test an hypothesis.
Here the given statement 'A chemist mixes sodium with water and witnesses a violent reaction between the metal and water,' can be classified as an observation as it explains what the chemists observes as a result of his chemical experiment or test..
NaCl or sodium chloride is composed of two metals: the cation is Na + while the anion is the Cl-. In this case, when two metals form a bond, valence electrons are transferred. NaCl is an ionic compound. In 2, upon chemical change, the properties of the compound resulting from the reaction are somewhat closely related from the elemental properties.