In general chemistry, isotopes are substances that belong to one specific element. So, they all have the same atomic numbers. But they only differ in the mass numbers, or the number of protons and neutrons in the nucleus. In a nutshell, they only differ in the number of neutrons.
For Nickel, there are 5 naturally occurring isotopes. Their identities, masses and relative abundance are listed below
Isotope Abundance Atomic Mass
Ni-58 68.0769% <span>57.9353 amu
Ni-60 </span>26.2231% <span>59.9308 amu
Ni-61 </span>1.1399 % <span>60.9311 amu
Ni-62 </span>3.6345% <span>61.9283 amu
Ni-64 </span>0.9256% <span>63.9280 amu
To determine the average atomic mass of Nickel, the equation would be:
Average atomic mass = </span>∑Abundance×Atomic Mass
Using the equation, the answer would be:
Average atomic mass = 57.9353(68.0769%) + 59.9308(26.2231%) + 60.9311(1.1399%) + 61.9283(3.6345%) + 63.9280(0.9256%)
Average atomic mass = 58.6933 amu
Mercury is a homogenous mixture of two or more pure substances
Answer:
a scientific question
Procedure
Conclusion.
Explanation:
Scientific investigation is usually carried out to explain and give answers to natural phenomenon. Now, this scientific investigation is performed through the three main types as described in the question.
With that being said, the most common parts of all types of investigation are :
1. Scientific question: In this stage, questions are usually asked on the basis of observation made which could be answered.
2. Procedure: In this stage, the dimension of the steps are followed to answer and test the scientific question.
3. Conclusion: This is the primary aim that we check when done with our sample values
Answer: 12033 kJ of heat produced per kg of 
formed during the combustion of benzene
Explanation:
The balanced chemical equation for combustion of benzene is :
= -6278 kJ
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and 
for the reaction comes out to be negative.
(1kg=1000g)
According to stoichiometry :
12 moles of on combustion produce heat = 6278 kJ
Thus 23 mole of on combustion produce heat =
Thus 12033 kJ of heat produced per kg of formed during the combustion of benzene
