Depth where light intensity falls to one percent<span> of that at the surface, called the euphotic depth</span>
The correct statement : The atomic number of the radioactive nuclide is 90.
<h3>Further explanation</h3>
In the following element notation,

X = symbol of elemental atom
A = mass number
= number of protons + number of neutrons
Z = atomic number
= number of protons = number of electrons, on neutral elements
The symbol for a radioactive nuclide :

atomic number = 90
mass number = 234
number of neutrons = 234-90=144
number of protons = atomic number = 90
Hci acid its high preety cool
Answer:
pH = -log₁₀ [H⁺]
Explanation:
pH is a value in chemistry used in to measure solution trying to determine each quality, purity, risks for health of some products, etc.
As you write in the question, [H⁺] = 10^(-pH)
Using logarithm law (log (m^(p) = p log(m):
log₁₀ [H⁺] = -pH
And
<h3>pH = -log₁₀ [H⁺]</h3>
Answer:
The mole fraction of ethanol is 0.6. A 10 mL volumetric pipette must be used for to measure the 10 mL of ethanol. The vessel should be clean and purged.
Explanation:
For calculating mole fraction of ethanol, the amount of moles ethanol must be calculated. Using ethanol density (0.778 g/mL), 10 mL of ethanol equals to 7.89 g of ethanol and in turn 0.17 moles of ethanol. The same way for calculate the amount of water moles (ethanol density=0.997 g/mL). 2 mL of water correspond to 0.11. The total moles are: 0.17+0.11=0.28. Mole fraction alcohol is: 0.17/0.28=0.6