Answer:<span>d. 145 minutes
</span>
Half-life is the time needed for a radioactive to decay half of its weight. The formula to find the half-life would be:
Nt= N0 (1/2)^ t/h
Nt= the final mass
N0= the initial mass
t= time passed
h= half-life
If 25.0% of the compound decomposes that means the final mass would be 75% of initial mass. Then the half-live for the compound would be:
Nt= N0 (1/2)^ t/h
75%= 100% * (1/2)^ (60min/h)
3/4= 1/2^(60min/h)
log2 3/4 = log2 1/2^(60min/h)
0.41503749928 = -60min/h
h= -60 min / 0.41503749928= 144.6min
Answer:
shorter wavelength = alpha wave
Explanation:
Given that,
The alpha wave has a frequency of 5 Hz and the beta wave has a frequency of 2 Hz.
We need to compare the wavelengths of these two waves.
For alpha wave,
For beta wave,
From the above calculations, we find that the wavelength of the alpha wave is shorter than the wavelength of the beta wave.
4d7 , 3s2 will be the valence shell electronic configuration of a neutral atom of cobalt!
Answer:
A. to determine the efficiency of the reaction
Explanation:
- Percentage is the ratio of the actual yield to theoretical yield as a percentage. It is calculated by dividing the actual yield by theoretical yield then multiplying by 100%.
- Calculation of percentage yield is important as it helps in the determination of efficiency of a reaction. For example in most industries for the purpose of making the most product with the least waste.
- Additionally, calculating the percentage yield helps in determining other products that may be formed during the reactions.
