A raíz de la evidencia, elegimos el decapante en gel.

Here, a raíz de means something like as a result of, following, or in light of. It introduces the reason or trigger for what happened next.

It is a fixed expression, so it is best learned as a chunk. Although raíz literally means root, you should not translate a raíz de word for word.

In this sentence, it signals that the choice was made because of the evidence.

They are similar, but not identical.

• a raíz de often suggests that something happened in response to or following something else
• debido a is a more direct due to / because of
• por is broader and can express many things, including cause

So a raíz de la evidencia has a slightly more natural sense of on the basis of what the evidence showed or following the evidence.

For example:

• A raíz de los resultados, cambiamos el método.
• Debido a los resultados, cambiamos el método.

Both work, but the first feels a bit more like the change came after considering those results.

The comma separates the introductory phrase A raíz de la evidencia from the main clause elegimos el decapante en gel.

In Spanish, this kind of comma is common when a phrase giving time, cause, condition, or context comes first, especially in more careful or formal writing.

Without the comma, the sentence would still often be understood, but with the comma it reads more clearly and naturally in this style.

Yes, it can, especially in scientific, academic, journalistic, or formal contexts. However, this is an area learners often ask about because evidencia does not always line up perfectly with English evidence.

In everyday Spanish, especially when meaning proof or pieces of evidence, people often use:

• prueba
• pruebas
• indicios
• datos

So la evidencia is understandable and natural in many contexts, but depending on context, a native speaker might also say las pruebas or los datos.

Because the verb already tells you the subject.

In elegimos, the ending -imos shows that the subject is we (nosotros/nosotras). Spanish often leaves subject pronouns out when they are not needed.

So:

• Elegimos el decapante en gel = We chose the gel stripper

You could say Nosotros elegimos..., but that usually adds emphasis or contrast, as in:

• Nosotros elegimos el decapante en gel, no el líquido.

It can mean either, depending on context.

Elegimos is one of those forms that is identical in:

• the present tense: we choose
• the preterite: we chose

So the surrounding context tells you which one is meant.

In a sentence like this, especially with A raíz de la evidencia, it very often sounds like a completed past action: we chose.

If the broader context were about a current procedure or habit, it could also mean we choose.

El points to a specific product or option, while un would mean a non-specific one.

So:

• el decapante en gel = the specific gel stripper
• un decapante en gel = a gel stripper, any one of that type

In this sentence, el suggests that the speaker has a particular product or option in mind, probably one already known in the conversation or one selected from several alternatives.

Decapante is a stripping product, often used to remove paint, varnish, or similar coatings. In British English, this might be understood as something like a paint stripper or stripping agent.

En gel means in gel form or gel-based.

This structure is very common in Spanish when talking about the format or physical form of a product:

• champú en seco
• detergente en polvo
• pintura en spray

So decapante en gel means the decapant/stripper is presented as a gel, not as a liquid, spray, etc.

Because en + noun is the usual way to express the form, presentation, or state of a product.

So:

• en gel = in gel form
• de gel would usually sound odd here

Compare:

• jabón en pastilla
• desinfectante en spray
• pegamento en barra

Spanish is treating gel as the format of the product, not as the material it is made from.

Yes. You could also say:

Elegimos el decapante en gel a raíz de la evidencia.

That is grammatical too. The difference is mainly one of emphasis and style.

• A raíz de la evidencia, elegimos... puts the cause first and sounds a bit more formal or written
• Elegimos... a raíz de la evidencia puts the action first and the reason after it

Both are correct; the version with a raíz de at the beginning highlights the reason more strongly.

It is common in technical, DIY, decorating, renovation, and hardware-store contexts. A native speaker in Spain would understand it in the right setting, especially if the topic is removing paint or varnish.

It is not the kind of word people use every day in general conversation, but it is perfectly normal for this kind of subject matter.