Sprickan syns efter bränningen.

Because Swedish usually marks definiteness by adding the definite article to the end of the noun.

• en spricka = a crack
• sprickan = the crack

So sprickan is the definite form of an en-word noun.

Syns is the present tense passive form of se (to see).

So:

• se = to see
• ses = is seen
• syns = is visible / can be seen / shows up

In this sentence, sprickan syns means something like the crack is visible or the crack can be seen.

It does not mean that the crack is actively doing the seeing. It is the thing that becomes visible.

This is a very common learner question. Although ses is the regular passive of se, Swedish often uses synas in contexts where something is visible or noticeable.

So:

• ses = is seen
• syns = is visible / can be seen

In many everyday situations, syns sounds more natural when you mean that something can be seen with the eye.

They are very close in meaning.

• Sprickan syns = The crack is visible / can be seen
• Sprickan är synlig = The crack is visible

The version with syns often feels a bit more natural in ordinary speech when talking about whether something can be seen.
The version with är synlig is also correct, but slightly more descriptive or formal in tone.

Bränningen is the definite form of bränning.

In this kind of sentence, especially in a craft or ceramics context, bränning usually means firing: heating something in a kiln or oven.

So:

• en bränning = a firing
• bränningen = the firing

So efter bränningen means after the firing.

Depending on context, bränning can have other meanings too, but firing is the most likely one here.

Because Swedish normally uses the simple definite noun when English would often say the + noun.

So:

• efter bränningen = after the firing

You would use den bränningen only if you want extra emphasis or contrast, for example:

• inte efter den första bränningen, utan efter den andra
  not after the first firing, but after the second

In a neutral sentence, efter bränningen is the natural choice.

Because Swedish usually puts the definite article at the end of the noun instead of using a separate word like English the.

So:

• the crack = sprickan
• the firing = bränningen

A separate definite word like den is only added in certain cases, such as with adjectives:

• den stora sprickan = the big crack

Without an adjective, sprickan by itself already means the crack.

The structure is:

• Sprickan = subject
• syns = verb
• efter bränningen = time expression

So the basic order is:

Subject + verb + adverbial

That is a very normal Swedish main-clause pattern.

Yes. That is also correct.

If you move efter bränningen to the front, Swedish still keeps the verb in second position:

• Efter bränningen syns sprickan.

This is standard Swedish V2 word order.
So both of these are correct:

• Sprickan syns efter bränningen.
• Efter bränningen syns sprickan.

The difference is mainly emphasis. The second version puts more focus on after the firing.

In this sentence, yes: efter bränningen is after the firing, where bränningen is a noun.

If you want to say after doing something, Swedish often uses a clause instead, for example:

• efter att den har bränts = after it has been fired

So:

• efter bränningen = after the firing
• efter att den har bränts = after it has been fired

Both are possible, but the sentence you were given uses the shorter noun phrase.

Spricka is an en-word in Swedish.

So its forms are:

• en spricka = a crack
• sprickan = the crack
• sprickor = cracks
• sprickorna = the cracks

This is useful because Swedish noun forms depend on whether the noun is an en-word or an ett-word.

Bränning is also an en-word.

Its forms are:

• en bränning = a firing
• bränningen = the firing
• bränningar = firings
• bränningarna = the firings

The ending -ing often appears in nouns made from verbs, and many such nouns are en-words.

A learner-friendly guide:

• ä sounds somewhat like the vowel in English bed, though not exactly the same.
• ng in Swedish is usually like the ng sound in sing.
• The g is not pronounced separately here.

So bränningen is roughly pronounced like BREN-ing-en, with Swedish vowels and stress.

Also, sprickan has the stress on the first syllable: SPRICK-an.

Sometimes English speakers are tempted to translate too literally, but here syns does not mean shows in the sense of displays or demonstrates.

In this sentence, it means:

• is visible
• can be seen
• shows up

So Sprickan syns is better understood as The crack is visible than as The crack shows.

Yes, very natural.

In contexts like ceramics, glass, metalwork, or any material process involving heating, Sprickan syns efter bränningen sounds like a normal factual statement: the crack becomes visible after the item has been fired.

It is short, clear, and idiomatic Swedish.