Керамическая масса уже готова.

Because готова is the short form of the adjective готовый.

In Russian, short-form adjectives are very commonly used as the predicate after the subject, especially for states like ready, busy, happy, necessary, and so on.

So:

• Керамическая масса готова. = The ceramic mass is ready.
• готова = short-form predicate adjective

By contrast, готовая is the full form, which is more naturally used before a noun:

• готовая масса = ready/prepared mass

So in this sentence, готова is the normal choice.

In Russian, the verb to be is usually omitted in the present tense.

So:

• Керамическая масса уже готова. literally looks like Ceramic mass already ready.

But it naturally means:

• The ceramic mass is already ready.

If the sentence were in the past or future, Russian would use forms of быть:

• Керамическая масса была готова. = The ceramic mass was ready.
• Керамическая масса будет готова. = The ceramic mass will be ready.

Because the noun масса is feminine singular.

In Russian, adjectives agree with the noun they describe, and predicate adjectives also agree with the subject.

So:

• масса = feminine singular
• керамическая = feminine singular adjective
• готова = feminine singular short-form adjective

That is why both words take feminine forms.

Compare:

• материал уже готов = masculine
• смесь уже готова = feminine
• изделие уже готово = neuter
• материалы уже готовы = plural

It is in the nominative case, because it is the subject of the sentence.

The subject is the thing that is being described as ready.

So:

• керамическая масса = nominative singular

A useful detail: готова is a short adjective, and short adjectives do not show case the way full adjectives do. They mainly show gender and number.

Уже means already.

It shows that the state has been reached by this point:

• Керамическая масса уже готова. = The ceramic mass is already ready.

In context, уже can sometimes also carry a sense like by now or at this point.

It is a very common word in Russian and often appears before the part of the sentence it relates to.

Yes, Russian word order is fairly flexible, though some versions sound more neutral than others.

The most neutral version here is:

• Керамическая масса уже готова.

Other orders are possible for emphasis, for example:

• Уже керамическая масса готова.
• Уже готова керамическая масса.

These may sound more marked or context-dependent. For a learner, the original order is the safest and most natural.

Because in Russian, adjectives usually come before the noun they describe, just as in English.

So:

• керамическая масса = ceramic mass

You can sometimes move the adjective after the noun for special emphasis or style, but that is not the normal neutral order.

So the basic pattern is:

• adjective + noun
• керамическая масса

Not in the everyday physics sense of mass.

In technical or industrial Russian, масса can mean a mixture, paste, compound, or body used in production. In ceramics, керамическая масса often refers to the ceramic material mixture before or during shaping.

So even though the word is literally mass, in this context it is better understood as a ceramic mixture/body.

This is a good example of a word whose technical meaning is broader than its most obvious English look-alike.

The stress is:

• керами́ческая ма́сса уже́ готова́

A rough pronunciation guide:

• керами́ческая = keh-rah-MEE-chee-skah-yah
• ма́сса = MAHs-sah
• уже́ = oo-ZHEH
• готова́ = gah-tah-VAH

A very important point: in готова́, the stress is on the last syllable.

The structure stays the same, but готов changes to match the gender and number of the subject.

Examples:

• Материал уже готов. = masculine
• Смесь уже готова. = feminine
• Изделие уже готово. = neuter
• Материалы уже готовы. = plural

So the pattern is:

• masculine: готов
• feminine: готова
• neuter: готово
• plural: готовы

Usually, not in neutral standard Russian.

For a simple statement like The ceramic mass is ready, Russian normally prefers the short form:

• Керамическая масса готова.

The full form готовая sounds much more natural when it directly modifies the noun:

• готовая керамическая масса = ready/prepared ceramic mass

If you use готовая after the noun, it can sound marked, contrastive, or less natural in a basic statement.

So as a learner, the best choice here is:

• Керамическая масса уже готова.