Answer:
Therefore it will take 7.66 hours for 80% of the lead decay.
Explanation:
The differential equation for decay is


Integrating both sides
ln A= kt+c₁

[
]
The initial condition is A(0)= A₀,


.........(1)
Given that the
has half life of 3.3 hours.
For half life
putting this in equation (1)

[taking ln both sides,
]

⇒k= - 0.21
Now A₀= 1 gram, 80%=0.8
and A= (1-0.8)A₀ = (0.2×1) gram = 0.2 gram
Now putting the value of k,A and A₀in the equation (1)




⇒ t≈7.66
Therefore it will take 7.66 hours for 80% of the lead decay.
Answer:
Option A.
Explanation:
Option A directly tests the cause and effect. Option B simply argues it argumentatively without any solid evidence to show cause and effect. Option C only shows correlation and Option D only shows correlation as well.
Answer:
D
Explanation:
If the deer leave the forest then they are avoiding compotation
Answer:
75000 Hz
Explanation:
f = V / λ (f= frequency, v=velocity of wave, lambda= wavelength)
alternatively, f = c / λ (f= frequency, c= speed of light- 3.00x10^8 m/s, lambda= wavelength)
f= [3.00x10^8 m/s]/[4000 m]
=75000 Hz
First, we have to get how many grams of C & H & O in the compound:
- the mass of C on CO2 = mass of CO2*molar mass of C /molar mass of CO2
= 0.5213 * 12 / 44 = 0.142 g
- the mass of H atom on H2O = mass of H2O*molar mass of H / molar mass of H2O
=0.2835 * 2 / 18 = 0.0315 g
- the mass of O = the total mass - the mass of C atom - the mass of H atom
= 0.3 - 0.142 - 0.0315 = 0.1265 g
Convert the mass to mole by divided by molar mass
C(0.142/12) H(0.0315/2) O(0.1265/16)
C(0.0118) H(0.01575) O(0.0079) by dividing by the smallest value 0.0079
C1.504 H3.99 O1 by rounding to the nearst fraction
C3/2 H4/1 )1/1 multiply by 2
∴ the emprical formula C3H8O2