Answer:
there r 118 elements in periodic table..
hope it helps.
Using the exponential decay model; we calculate "k"
We know that "A" is half of A0
A = A0 e^(k× 5050)
A/A0 = e^(5050k)
0.5 = e^(5055k)
In (0.5) = 5055k
-0.69315 = 5055k
k = -0.0001371
To calculate how long it will take to decay to 86% of the original mass
0.86 = e^(-0.0001371t)
In (0.86) = -0.0001371t
-0.150823 = -0.0001371 t
t = 1100 hours
Answer:
173.83 mmHg is the vapor pressure of a ethylene glycol solution.
Explanation:
Vapor pressure of water at 65 °C=
Vapor pressure of the solution at 65 °C= 
The relative lowering of vapor pressure of solution in which non volatile solute is dissolved is equal to mole fraction of solute in the solution.
Mass of ethylene glycol = 22.37 g
Mass of water in a solution = 82.21 g
Moles of water=
Moles of ethylene glycol=



173.83 mmHg is the vapor pressure of a ethylene glycol solution.
Answer:
Regions of the Electromagnetic Spectrum
Wavelength (m)Frequency (Hz)Radio> 1 x 10-1< 3 x 109Microwave1 x 10-3 - 1 x 10-13 x 109 - 3 x 1011Infrared7 x 10-7 - 1 x 10-33 x 1011 - 4 x 1014Optical4 x 10-7 - 7 x 10-74 x 1014 - 7.5 x 1014