Answer:
The correct option is: b. pH 6.4-8.0
Explanation:
Phenol red is a weak acid that is used as a pH indicator and exists in the form of stable red crystals.
<u>The color of the phenol red solution changes from yellow to red when the change in pH is observed. The color of phenol red transitions from yellow to red when the pH is 6.8 - 8.2 or 6.4 - 8.0</u>
Above the pH of 8.2, the phenol red solution turns a bright pink in color.
The substance that gets dissolved is the solute and the substance that dissolves the solute is the solvent. Example: water is a solvent and salt is a solute
Answer:
Explanation:
average speed=distance travelled/time taken
distance=speed*time
15*10=150 m
1200 m/min=20 m/s
0.17 minute=10.2 seconds
20*10.2=204 m
2500 cm/s=25 m/s
5000 milliseconds=5 seconds
25*5=125 m
125+150+204=479 m
10.2+5+10=25.2
479/25.2=<u>19.0 </u>
Answer:
The mass number (A) of an atom is the total number of protons and neutrons in its nucleus. ... Because electrons have virtually no mass, just about all the mass of an atom is in its protons and neutrons. Therefore, the total number of protons and neutrons in an atom determines its mass in atomic mass units (Table 4.5. 1).