By the 1900s, what type of evidence was being collected at crime scenes to positively identify suspects by one particularly unique trait?

fingerprints
stolen goods
dna samples
photographs

The correct answer would be - fingerprints.

Explanation:

Fingerprints are unique in every person. Fingerprint patterns are distinct in each and every person so it is easy to identify or match the person on the basis of their fingerprints.

This unique pattern makes it possible to use prints taken from a crime scene to either eliminate a suspect from the suspect list or match suspect to the scene. fingerprints can be collected from different types of surfaces.

Thus, the correct answer is fingerprints.

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.

thinking it would be d not too sure but i think it's right