Answer:
B..........................
Answer:
90yrs
Explanation:
Half life is the time taken for half of an original radioactive material to decay by half.
For the sample;
Half - life = 45yrs
Original amount = 600cpm
Start Number of atoms
0yrs 600cpm
First half life
45yrs 300cpm
Second half life
90yrs 150cpm
The new volume of the gas is 144 mL.
<u>Explanation:</u>
At STP, the temperature is 273 K an pressure is 1 atm.
1 atm=101kPa
Given that initial volume V1=36 mL
Initial pressure P1=1atm=101 kPa
Final pressure P2=25.3kPa
We have to determine the final volume V2
According to Boyle's law
=144 mL
Final volume =144mL
Answer:
The answer to the question is 275 years
Explanation:
Here we have
The decay rate is given by
dN/dt = -λN
or dN/N = -λdt
Integrating the above equation with limits N and N₀ we have
㏑(N/N₀) = -λt
Note that the half life = (㏑ 2)/λ
From where λ = 0.693/5730 = 1.21 × 10⁻⁴
∴ ㏑(14.8/15/3) = -1.21 × 10⁻⁴ × t
or t = 275 years
<span>Lemon juice, pH of 2.
Vinegar, pH of 2.
<span>Coca-Cola (Coke), pH from 2 to 4.
</span>Battery acid, pH of 0.
<span>Black coffee, pH of around 5.</span></span>