"<span>Changes of state are physical changes. They occur when matter absorbs or loses energy. Processes in which matter changes between liquid and solid states are freezing and </span>melting<span>. Processes in which matter changes between liquid and gaseous states are vaporization, evaporation, and condensation."</span>
So back in 1665 Robert hook was able to view cells and describe them along with pictures, the reason he was able to see cells was because the microscope was invented a bit before, which allowed him to think about things differently, he was looking at a cork and saw squared objects, these objects were cells, according to him.
So while the cork was the reason he discovers cells on it in the first place,
The microscope was what allowed him to do that
So it’s (HOOKE LOOKING AT A CORK)
And it’s (THE INVENTION OF THE MICROSCOPE)
Answer:
Option d. 7
Explanation:
A mixture of a strong base and a strong acid produce a neutral salt and water.
This is the reaction of neutralization:
HCl + NaOH → NaCl + H₂O
NaCl → Na⁺ + Cl⁻
Sodium chloride is neutral salt which does not give H⁻ neither OH⁻ to medium, that's why pH is neutral.
Both ions are derivated from a strong acid and base so they do not make hydrolisis. They are a conjugate pair of a weak acid and base. The reactions can not occur:
Cl⁻ + H₂O ← OH⁻ + HCl
Na⁺ + H₃O⁺ ← NaOH + H₂O
The answer you are looking for is True
I think thee correct answer from the choices listed above is option D. <span>When a physical change in a sample occurs, composition of the sample does not change. It stays the same. Also, the properties of the sample will still be the same. Hope this answers the question.</span>
