Answer:
Billions in the known universe!
Explanation:
Because there are approximately 100 billion galaxies in the observable universe.
Hope it helps!
I disagree, because a physical change changes the form, and a chemical change is a process where one or more substances are altered into new substances.
Answer:
all the elements in the same period have the same valence electrons.
The answer is: H₃PO₄.
A phosphoric acid is three protic acid, which means that in water release tree protons.
Phosphoric acid ionizes in three steps in water.
First step: H₃PO₄(aq) ⇄ H₂PO₄⁻(aq) + H⁺(aq).
Second step: H₂PO₄⁻(aq)⇄ HPO₄²⁻(aq) + H⁺(aq).
Third step: HPO₄²⁻(aq) ⇄ PO₄³⁻(aq) + H⁺(aq).
Species that are present: H₃PO₄, H₂PO₄⁻, HPO₄²⁻, PO₄³⁻ and H⁺.
A buffer can be defined as a substance that prevents the pH of a solution from changing by either releasing or absorbing H⁺ in a solution.
Buffer is a solution that can resist pH change upon the addition of an acidic or basic components and it is able to neutralize small amounts of added acid or base, pH of the solution is relatively stable.