Answer:
pH = 9.2
Explanation:
pH+pOH=14
But pOH= -log[OH]= -log[1.58×10^-5]= 4.8
We can now say
4.8+pH= 14
pH= 14-4.8= 9.2
Answer:
The percentage efficiency of the electrical element is approximately 82.186%
Explanation:
The given parameters are;
The thermal energy provided by the stove element,
= 3.34 × 10³ J
The amount thermal energy gained by the kettle,
= 5.95 × 10² J
The percentage efficiency of the electrical element in heating the kettle of water, η%, is given as follows;

Therefore, we get;

The percentage efficiency of the electrical element, η% ≈ 82.186%.
All the positive charge of an atom is contained in the nucleus, and originates from the protons. Neutrons are neutrally-charged. Electrons, which are negatively-charged, are located outside of the nucleus.
I think it is b..................................................