If all the baryons (composite particles made up of three quarks) in the universe were composed solely of top and bottom quarks, the resulting particles would not form elements as we typically understand them.
Elements, as we know them, are formed through the combination of protons and neutrons in atomic nuclei. Protons are baryons made up of two up quarks and one down quark, while neutrons consist of two down quarks and one up quark. The combination of protons and neutrons in various configurations forms atomic nuclei, and different elements are distinguished by the number of protons in the nucleus, known as the atomic number.
If all baryons were composed of top and bottom quarks, the resulting particles would be different from protons and neutrons. Top quarks have a charge of +2/3 and a large mass, while bottom quarks have a charge of -1/3 and a relatively smaller mass. The combination of three top or bottom quarks would result in particles with significantly different properties compared to protons and neutrons.
These hypothetical particles, known as exotic baryons, have not been observed in nature. Their behavior and stability would depend on various factors, including their mass, charge, and the nature of the strong nuclear force acting between the constituent quarks.
In summary, if the universe consisted solely of top and bottom quarks forming baryons, it would not resemble the universe as we know it, with its diverse array of elements formed by the combination of protons and neutrons. The properties and stability of these hypothetical exotic baryons would be significantly different from those of ordinary matter.