Achemistry teacher carried out several demonstrations, and students recorded their observations. for one of the demonstrations, a student concluded that a physical change took place, but not a chemical change. which of the following observations could the student have made of the results of the demonstration?

The given question is incomplete. The complete question is:

A chemistry teacher carried out several demonstrations, and students recorded their observations. For one of the demonstrations, a student concluded that a physical change took place, but not a chemical change. Which of the following observations could the student have made of the results of the demonstration?

a) Two colorless solutions were combined, and the resulting solution was pink.

b)  When a solid was added to a liquid, sparks were produced.

c) One piece of solid substance was changed into small pieces.

d) When two solutions were combined, a precipitate formed.

One piece of solid substance was changed into small pieces.

Explanation:

Physical change is defined as the change in which shape and size of a substance changes, There is no change in the composition of the substance as no new substance is forming. It is usually an reversible reaction.

Chemical change is defined as the change in which a change is the chemical composition takes place resulting in the formation of new substance. It is usually an irreversible reaction.

Indicators showing chemical changes are :

Color change

Characteristic odor

Formation of bubbles

Formation of precipitate

Thus the given change is a physical change as only the physical state i.e. size of solid substance was changed into small pieces.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.