Я открыла вклад в банке на год.

Открыла is the past tense, feminine singular form of открыть.

• открыть = to open
• открыл = he opened
• открыла = she opened
• открыли = they opened / you opened (formal/plural)

So this sentence tells us that the speaker is female.

Also, открыть is perfective, so открыла suggests a completed action: she successfully opened the deposit.

In this sentence, вклад means a bank deposit, often a fixed-term deposit.

It does not mean a general contribution here, even though вклад can have that meaning in other contexts.

So:

• открыть вклад = to open a deposit
• вклад в банке = a bank deposit

This is a normal financial expression in Russian.

Russian commonly uses the expression открыть вклад, literally to open a deposit.

This is just a standard collocation. Languages often package financial actions differently.

Compare:

• открыть счёт = open an account
• открыть вклад = open a deposit

So even if English might phrase it differently, открыть вклад is natural Russian.

Because в банке is about location: in/at the bank.

After в, Russian uses:

• Prepositional case for location: в банке
• Accusative case for motion into somewhere: в банк

So:

• Я была в банке = I was at the bank
• Я пошла в банк = I went to the bank

In your sentence, the deposit was opened at the bank, so в банке is correct.

Because after в meaning in/at, the noun usually takes the prepositional case.

The noun changes like this:

• банк = bank
• в банке = in/at the bank

So банке is simply the prepositional form of банк.

На год means for one year.

It shows the term or duration of the deposit. So the idea is that the deposit was opened with a one-year term.

This use of на is very common for periods of time:

• на час = for an hour
• на неделю = for a week
• на месяц = for a month
• на год = for a year

Because на here expresses duration/term, and that use normally takes the accusative case.

So:

• год is the accusative form here
• на год = for a year

For masculine inanimate nouns like год, nominative and accusative often look the same, so you just see год.

Yes, you could say на один год, and it would mean the same thing.

But на год is usually more natural and more common unless you want to emphasize the number one.

Compare:

• на год = for a year
• на один год = for exactly one year / for one year specifically

So in an ordinary sentence, на год is the better choice.

Yes, Я can often be omitted in Russian if the subject is clear from context.

So both of these are possible:

• Я открыла вклад в банке на год.
• Открыла вклад в банке на год.

Russian often drops subject pronouns when they are obvious.

However, Я may be kept for:

• clarity
• contrast
• emphasis

So with Я, the sentence sounds a bit more explicit or neutral in isolation.

No, Russian word order is fairly flexible.

Я открыла вклад в банке на год is a neutral, natural order.

But you can move parts around for emphasis:

• В банке я открыла вклад на год.
  Emphasis on at the bank
• На год я открыла вклад в банке.
  Emphasis on for a year
• Вклад в банке я открыла на год.
  Emphasis on the deposit

The basic meaning stays similar, but the focus changes.

They are related financial words, but they are not the same.

• счёт = account
• вклад = deposit, especially a term deposit

For example:

• открыть счёт в банке = to open a bank account
• открыть вклад в банке = to open a deposit in a bank

So if you use счёт instead of вклад, you change the meaning.

Открывала is the imperfective past form.

Compare:

• открыла = opened, completed the action
• открывала = was opening / used to open / opened in a more process-focused or repeated sense

In this sentence, открыла is the natural choice because it describes a finished, one-time action.

If you said Я открывала вклад в банке на год, it would sound less natural by itself unless there is extra context, for example:

• talking about the process
• contrasting attempts
• describing repeated actions

Because Russian has no articles.

So вклад can mean:

• a deposit
• the deposit

The exact meaning depends on context.

That is normal in Russian. Learners have to get used to understanding definiteness from the situation, not from separate words like a or the.