Answer:
yeep the answer is 3... i just took the k12 test rn
Explanation:
Atomic size gradually decreases from left to right across the periodic table because within a period of elements, all electrons are added to the same shell. However, at the same time, protons are being added to the nucleus, making it more positively charged. The effect of increasing proton number is greater than that of the increasing electron number. Therefore, there is a stronger nuclear attraction. This means that the nucleus attracts the electrons more strongly, pulling the atom's electron shells closer to the nucleus. As a result, the atomic diameter of the atom decreases.
The atomic mass of sodium is 23. i hope that helps!
<u>Answer:</u> Copper is getting oxidized and is a reducing agent. Silver is getting reduced and is oxidizing agent.
<u>Explanation:</u>
Oxidation reaction is defined as the reaction in which an atom looses its electrons. Here, oxidation state of the atom increases.

Reduction reaction is defined as the reaction in which an atom gains electrons. Here, the oxidation state of the atom decreases.

Oxidizing agents are defined as the agents which oxidize other substance and itself gets reduced. These agents undergoes reduction reactions.
Reducing agents are defined as the agents which reduces the other substance and itself gets oxidized. These agents undergoes reduction reactions.
For the given chemical reaction:

The half reactions for the above reaction are:
<u>Oxidation half reaction:</u> 
<u>Reduction half reaction:</u> 
From the above reactions, copper is loosing its electrons. Thus, it is getting oxidized and is considered as a reducing agent.
Silver is gaining electrons and thus is getting reduced and is considered as an oxidizing agent.