This aristocratic household is:

the Noble Gases from the Periodic Table of parts.

Each line of the puzzle’s sample works as follows:

The final two digits of the yr are the atomic variety of one other (non-noble) Periodic Table aspect whose shortform image may be mixed with that of one of many seven noble gases to kind the identify of an animal.

In 1904, the primary individual bought married. The couple adopted a Bear.

Element 04 is Beryllium (Be). With Argon (Ar) these two symbols mix to make BeAr.

In 1913, the second individual bought married. The couple adopted a Lark.

Element 13 is Aluminium (Al). With Krypton (Kr) you may make lArK.

In 1952, the third individual bought married. The couple adopted a Tern.

Element 52 is Tellurium (Te). With Radon (Rn) you may make TeRn.

In 1983, the fourth individual bought married. The couple adopted an Ibex.

Element 83 is Bismuth (Bi). With Xenon (Xe) you may make iBeX.

In 1987, the fifth individual bought married. Which animal did the couple undertake?

Element 87 is Francium (Fr). The noble gasoline up to now unused whose image can kind an animal identify when mixed with ‘Fr’ is Oganesson (Og), giving us FrOg.

In which yr did the sixth individual get married?. The couple adopted a Hare.

The noble gasoline concerned on this query should be Helium (He). Since the ‘aristocrats’ are all marrying commoners (i.e. non-nobles), we will exclude Argon (Ar) from consideration, and as an alternative the opposite aspect concerned right here should be Radium (Ra), which as aspect 88 within the Periodic Table means the wedding occurred in 1988.

What is the identify of the single individual?

The ‘single individual’ – i.e. the one noble gasoline remaining – is Neon! (Sadly for them, they could have had two possibilities to wed in 1973 and 1985, however may need thought-about their potential matches somewhat too old style!)

So in abstract, the three questions yield the solutions:

A frog, 1988, and Neon.