Tin oxidizes less readily than iron due to differences in their chemical properties and place in the reactivity series. Tin (Sn) is less reactive compared to iron (Fe) and forms a passivation layer of oxide that protects it from further oxidation. When exposed to oxygen, iron reacts to form iron oxides, commonly known as rust, through a process that is relatively fast, especially in the presence of moisture. Tin, on the other hand, forms a stable oxide layer that adheres well to the surface, preventing further oxidation and corrosion. This is why tin is often used as a protective coating for metals, including iron and steel products, as in the case of tin-plated steel or cans. This protective layer is crucial for applications where resistance to corrosion is necessary. However, under certain conditions, such as acidic environments, tin can still corrode but at a much slower rate than iron.

Amino acids, the building blocks of proteins, can exist in two mirror-image forms: L (left-handed) and D (right-handed), referring to their optical activity. Most amino acids in nature and in proteins are in the L-form. The question of toxicity of D-amino acids (right-handed) is nuanced. Generally, D-amino acids are not inherently toxic. However, their presence and accumulation in the body can impact biological functions since most enzymes and receptors are designed to interact with L-amino acids. For example, D-amino acids can be found in the cell walls of bacteria, and some, like D-serine, play roles in human brain function. Yet, the unnatural presence of certain D-amino acids in the diet or through supplementation can lead to metabolic disturbances or interfere with normal protein synthesis, potentially leading to negative health effects. It's more about the context and balance rather than a blanket statement on toxicity.

Adhesion and scar tissue, while related, are not the same. Scar tissue forms as part of the natural healing process when the body repairs damaged tissue. It is the fibrous connective tissue that replaces normal tissue after injury. Adhesions, on the other hand, are bands of scar tissue that bind together tissues and organs that are not normally connected. They can develop after surgery, infection, inflammation, or trauma. Adhesions can cause organs to stick together, leading to pain, obstruction, or dysfunction of the affected organs. In summary, while both adhesion and scar tissue involve fibrous connective tissue growth as a healing or response mechanism to injury or trauma, adhesions specifically refer to the pathological bonding of tissues or organs that should normally be separate.