Introduction
DNA (deoxyribonucleic acid) is a double-stranded molecule that contains the genetic instructions used in the development and functioning of all known living organisms. The structure of DNA is composed of nucleotides, which consist of a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine).

Explanation
When it comes to the nitrogen bases in DNA, they always pair up in a specific way. Adenine (A) always pairs with thymine (T), and cytosine (C) always pairs with guanine (G). These base pairs are connected by hydrogen bonds, creating the double-stranded helical structure of DNA.

Equal Nitrogen Bases
In a double-stranded DNA molecule, the number of adenine bases is always equal to the number of thymine bases, and the number of cytosine bases is always equal to the number of guanine bases. This is known as Chargaff's rule, which states that the amount of adenine is equal to the amount of thymine, and the amount of cytosine is equal to the amount of guanine.

Unequal Nitrogen Bases
If a DNA molecule has unequal nitrogen bases, it means that the number of adenine bases is not equal to the number of thymine bases, or the number of cytosine bases is not equal to the number of guanine bases. This would disrupt the normal base-pairing pattern and cause instability in the DNA structure.

Single-stranded DNA
When a DNA molecule has unequal nitrogen bases, it is more likely to be single-stranded rather than double-stranded. In a single-stranded DNA molecule, there is no need for equal pairing of nitrogen bases because there is no complementary strand to pair with.

Conclusion
In conclusion, a DNA molecule with unequal nitrogen bases would most probably be single-stranded. This is because the normal base-pairing pattern is disrupted, and there is no complementary strand for the unequal nitrogen bases to pair with.