When a piece of zinc metal is carefully placed in a beaker of strong acid, bubbles form on the surface of the metal and begin to rise to the surface. The bubbles most likely indicate that
A.
a new substance is being produced.
B.
the zinc metal is melting.
C.
the acid solution is boiling.
D.
a physical change is occurring.

A.  a new substance is being produced.

Explanation:

The bubbles most likely indicates that a new substance is being produced by this reaction. In essence, we describe this sort of change as chemical change.

In a chemical change, new substances are usually produced. They are accompanied by the evolution or absorption of energy.

The reaction of Zinc with a strong acid to produce bubbles on the surface of the metal indicates a chemical change and the formation of a new kind of substance.

Take for example, let zinc reacts with hydrocholoric acid, HCl;

   Zn         +      2HCl      →    ZnCl₂     +     H₂

Since Zn is higher than Hydrogen in the activity series, it will displace it from HCl and liberate hydrogen gas as a product. This will cause the bubbles observed in the reaction.

This is a chemical change and new products have been formed.

B and D are wrong because they are both physical changes.

C is wrong because no information about such is provided by the problem statement.

So, when a piece of zinc metal combines with a strong acid, a new kind of substance is produced.

b

explanation:

mitosis

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .