The question is incomplete.
The complete question probably is
The pH scale for acidity is defined by pH = − log₁₀[H⁺] where [H⁺] is the concentration of hydrogen ions measured in moles per liter (M). A solution has a pH of 2.55. Find the hydrogen ion concentration.
Answer: -
0.003 M
Explanation: -
pH = − log₁₀[H⁺]
Thus the hydrogen ion concentration [H⁺] = 
= 
= 0.003 M
Answer:
O.
Explanation:
- The element which is oxidized is the element that losses electrons and its oxidation state be more positive.
- The element which is reduced is the element that gain electrons and its oxidation state be more negative.
<em> O goes from 0 to -2, so, it is the element that is reduced.</em>
The answer was 25
Do according to bodmas rule
Explanation:
As the Earth moves around the sun during a year, the northern half of the Earth is tilted towards the sun in the summer, making daytime longer than night. In winter, this reverses; the earth tilts away from the sun and nighttime becomes longer