N: 106Answer:
72 protons, 106 neutrons, 72 electrons.
Explanation:
to solve this use this simple method: APEMAN.
A= atomic number, P= Protons, E= Electrons.
M= Mass, A= atomic number, N= neutrons.
1. APE (atomic number, protons, electrons) are the same. since Hf (Hafnium) atomic number is 72, Hf has 72 protonsand ele ctrons.
2. to get Neutrons it will be mass-atomic number= neutrons.(M-A=N)
Hf mass= 178. So, 178-72= 106 neutrons.
Answer:
The answer is Potential energy
Hg + O2 --> HgO + O
Note that Mercury has a variable valency.
<u>Answer: </u>The correct answer is Option b.
<u>Explanation:</u>
Oxidizing agent is defined as the chemical reagent which helps the other chemical compound to get oxidized and itself gets reduced. The oxidation state for these species gets reduced because they are undergoing reduction reaction.
For the given chemical equation:

Oxidation state of Chromium is getting reduced from +6 to +3 and oxidation state of chlorine getting increased from -1 to 0.
Hence,
acts like and oxidizing agent because it is itself getting reduced to 
Therefore, the correct answer is Option b.
Answer: C
Explanation: i did this before