Answer: a) 
b) 
c) 
d) 
Explanation:
General representation of an element is given as:_Z^A\textrm{X}
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
It is characteristic of a particular element.
Atomic number = Number of electrons = Number of proton
a) Z 74, A 186:
b) Z 80, A 201:
c) Z 34, A 76:
d) Z 94, A 239.:
Aldol condensation involves the reaction of an acid or base with a carbonyl group producing a nucleophile that attacks another carbonyl compound to yield a β-hydroxyaldehyde or β-hydroxyketone compound.
<h3>What is aldol condensation?</h3>
The aldol condensation is a reaction in organic chemistry in which there is a reaction between an acid or base and a carbonyl group which then serves as the nucleophile that attcks a second carbonyl to yield a β-hydroxyaldehyde or β-hydroxyketone compound.
The aldol condensation may be acid catalysed or base catlysed. The question is incomplete hence the complete mechanimsms can not be decuced.
Learn more about aldol condensation: brainly.com/question/9415260
B I hope it’s right I don’t really help a lot but yeah lol
Answer: -
When bismuth-212 undergoes alpha decay, it becomes ²⁰⁸Tl
Explanation: -
Mass number of ²¹²Bi = 212
Atomic number of ²¹²Bi = 83
When alpha decay occurs the mass number decreases by 4 and the atomic number decreases by 2.
Mass number of daughter = 212 - 4 = 208
Atomic number of daughter = 83 - 2 = 81
It is the atomic number of Thallium Tl.
Thus the daughter nucleide is ²⁰⁸Tl.
