Answer:
When 2 or more pure substances are mixed together they form a mixture. If the mixture has its different components mixed evenly within the substance it is a homogeneous mixture. Whereas if the mixture has its different components mixed unevenly within the substance it is a heterogeneous mixture
Answer:
Hydrogen concentration = 7.94×10^-3 M
Explanation:
from potenz Hydrogen ( pH ) definition
pH = -log[H+]
2.1 = -log[H+]
2.1/-log = -log[H+]/-log
10^-2.1 = [H+]
[H+] = 7.94×10^-3M
Answer:
1.3x10⁻⁸ mol/L
Explanation:
<em>0.0013μmol, Calculate concentration in mol/L</em>
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To obtain concentration in mol/L we need to convert the μmoles to moles and mL to liters:
<em>Moles silver(II) oxide:</em>
0.0013μmol × (1mol / 1x10⁶μmol) = 1.3x10⁻⁹ moles
<em>Liters solution:</em>
100mL * (1L / 1000mL) = 0.1L
That means concentration in mol/L is:
1.3x10⁻⁹ moles / 0.1L =
<h3>1.3x10⁻⁸ mol/L</h3>
Answer:
so the third one
Explanation:
During the day, the sun heats up mountain air rapidly while the valley remains relatively cooler. Convection causes it to rise, causing a valley breeze. At night, the process is reversed. During the night the slopes get cooled and the dense air descends into the valley as the mountain wind.
For radioactive decay, we can relate current amount, initial amount, decay constant and time using:
N = No x exp(-λt)
Half-life = ln(2)/λ
λ = ln(2) / 5730
N/No = 80% = 0.8
0.8 = exp( -ln(2)/5730 x t)
t = 1844 years
