I need a a picture or the question
Answer:
The correct answer would be - c. A solid was added to water and the mixture was stirred until the solid was no longer visible
Explanation:
Photostabalizing is the process where a solid change its color in the presence of ultraviolet light, it is a chemical change, so the first option would not be the correct answer.
when two liquid or aqueous solutions are mixed together and form a solid substance, this reaction is known as precipitation and it is a chemical reaction too.
When a solid is placed in a liquid and after stirring it makes the solid vanish is a physical change known as dissolving character.
Thus, the correct answer is option C.
Answer:
15 protons
Explanation:
The atomic number always equals the number of protons inside the nucleus, so if the atomic number is 15, that means 15 protons are present.
Question is incomplete, complete question is;
A 34.8 mL solution of
(aq) of an unknown concentration was titrated with 0.15 M of NaOH(aq).

If it takes 20.4 mL of NaOH(aq) to reach the equivalence point of the titration, what is the molarity of
? For your answer, only type in the numerical value with two significant figures. Do NOT include the unit.
Answer:
0.044 M is the molarity of
(aq).
Explanation:
The reaction taking place here is in between acid and base which means that it is a neutralization reaction .
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

0.044 M is the molarity of
(aq).