Yes. A substance with both acidic and basic properties is called an amphoteric substance. Water, while generally regarded as neutral, is actually amphoteric. Sodium bicarbonate is also amphoteric. While it usually acts as a base, it can act as an acid under highly alkaline conditions.
Acid is a major chemical that behaves both as an acid and as a base. Another chemical would be KOH.
When it's mixed with a base
Sounds unlikely, since it's an acid, therefore can't be a base which is by definition the opposite of an acid.
The neutralization of a base, or an acid for that matter, is a chemical property, because you are reacting the base with an acid to change the base into a different compound. For example: NaOH (a strong base) + HNO3 (a strong acid) ---> NaNO3 + H2O
bubbles
yes.
Acid is a major chemical that behaves both as an acid and as a base. Another chemical would be KOH.
When it's mixed with a base
Sounds unlikely, since it's an acid, therefore can't be a base which is by definition the opposite of an acid.
An acid
A base will react with an acid.
Ammonia NH3 behaves as a base when it reacts with an acid because it accepts a proton and becomes NH4+.
The neutralization of a base, or an acid for that matter, is a chemical property, because you are reacting the base with an acid to change the base into a different compound. For example: NaOH (a strong base) + HNO3 (a strong acid) ---> NaNO3 + H2O
bubbles
Neutralization of acid with base (or vice verse)
It is a substance(chemical or natural) which changes colour in the presence of an acid or base.
It is usually straight-forward. If the chemical has acid in it, then it is an acid. So, citric acid, is an acid.