Το πάχος του τοιχώματος είναι σωστό και δεν υπάρχει φυσαλίδα αέρα.

πάχος is a neuter noun, so it takes the neuter article το.

• το πάχος = the thickness

A useful thing to notice is that many Greek nouns ending in -ος are masculine, but not all of them. πάχος is one of the neuter ones, so you have to learn its gender with the article.

του τοιχώματος is the genitive singular, and it means of the wall or of the wall layer / wall structure, depending on context.

So:

• το πάχος του τοιχώματος = the thickness of the wall

This is a very common Greek pattern:

• the X of the Y
  → το X του Y

Here:

• το πάχος = the thickness
• του τοιχώματος = of the wall

τοίχωμα and τοίχος are related, but they are not always used in exactly the same way.

• τοίχος usually means wall in the everyday sense, like a room wall.
• τοίχωμα often appears in technical, medical, scientific, or engineering contexts, where it means something like wall, lining, or side wall of a structure, container, organ, tube, etc.

So in a technical sentence like this, τοιχώματος sounds natural.

Because σωστό agrees with πάχος, and πάχος is neuter singular.

Greek adjectives agree with the noun they describe in:

• gender
• number
• case

So:

• masculine: σωστός
• feminine: σωστή
• neuter: σωστό

Since the subject is το πάχος, the adjective must be σωστό.

In this sentence, είναι is the normal way to say is:

• Το πάχος του τοιχώματος είναι σωστό.
  = The thickness of the wall is correct.

Greek sometimes omits forms of to be in very informal speech, headlines, labels, or notes, but in a full standard sentence like this, είναι is the expected form.

Literally, δεν υπάρχει means does not exist or is not present.

In natural English, it often becomes:

• there is no ...
• there isn’t any ...

So:

• δεν υπάρχει φυσαλίδα αέρα
  = there is no air bubble

This is a very common Greek way to express existence or presence.

Because the noun that follows is singular:

• φυσαλίδα = bubble (singular)

So Greek uses singular υπάρχει:

• δεν υπάρχει φυσαλίδα αέρα
  = there is no air bubble

If it were plural, you would use υπάρχουν:

• δεν υπάρχουν φυσαλίδες αέρα
  = there are no air bubbles

After υπάρχει / δεν υπάρχει, Greek very often uses a noun without an article when it means there is / there is no something.

So:

• δεν υπάρχει φυσαλίδα αέρα
  = there is no air bubble

This is more natural here than using a definite article.

If you said δεν υπάρχει η φυσαλίδα αέρα, that would sound more like:

• the air bubble is not there
• referring to a specific bubble already known in the conversation

So the article changes the meaning.

Here αέρα is genitive singular, meaning of air:

• φυσαλίδα αέρα = bubble of air = air bubble

This can be confusing because for the noun αέρας:

• nominative: ο αέρας
• genitive: του αέρα
• accusative: τον αέρα

So the genitive and accusative singular have the same form: αέρα.

In this sentence, it is genitive, because it depends on another noun:

• bubble of air

Yes, it is a very natural combination.

• φυσαλίδα = bubble
• αέρα = of air

So φυσαλίδα αέρα means air bubble, and it works much like an English noun + noun expression, even though Greek builds it as noun + genitive.

Similar Greek patterns are very common:

• ποτήρι νερού = glass of water
• μπουκάλι κρασιού = bottle of wine

Greek word order is flexible, but the version here is the most neutral and straightforward:

• Το πάχος του τοιχώματος είναι σωστό...

It starts with the topic/subject, then gives the comment about it.

You could change the order for emphasis, but the original is the most standard for technical or descriptive language.

Yes. και simply connects the two statements:

• Το πάχος του τοιχώματος είναι σωστό
  και
• δεν υπάρχει φυσαλίδα αέρα

So the sentence is made of two coordinated parts:

1. The wall thickness is correct
2. There is no air bubble

You would remove δεν:

• υπάρχει φυσαλίδα αέρα
  = there is an air bubble

So:

• Δεν υπάρχει φυσαλίδα αέρα.
  = There is no air bubble.
• Υπάρχει φυσαλίδα αέρα.
  = There is an air bubble.

This is a useful pair to memorize:

• υπάρχει = there is
• δεν υπάρχει = there is not / there is no

It has two main clauses joined by και:

1. Το πάχος του τοιχώματος είναι σωστό

   • subject: Το πάχος του τοιχώματος
   • verb: είναι
   • complement: σωστό

2. δεν υπάρχει φυσαλίδα αέρα

   • negation: δεν
   • verb: υπάρχει
   • noun phrase: φυσαλίδα αέρα

So a literal breakdown would be:

• The thickness of the wall is correct and there does not exist an air bubble.

And the natural English meaning is:

• The wall thickness is correct and there is no air bubble.