Answer:
90.2 da
Explanation:
The <em>half-life</em> of iron-59 (45.1 da) is the time it takes for half the Fe to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Time Percent Fraction
<u>half-lives</u> <u>days</u> <u>remaining</u> <u>remaining
</u>
1 45.1 50 ½
2 90.2 25 ¼
3 135 12.5 ⅛
4 180 6.25 ¹/₁₆
We see that 25 % remains after two half-lives or 90.2 da.
Assuming you meant a 0.7 mole sample of a gas, we can approximate this by assuming that the gas is acting ideally, and use the ideal gas law PV=nRT. Using the following values:
P = 1.2 Atm
V = 0.170 L
n = 0.7 mol
R = 0.08206 L-atm/mol-K
We can rewrite the equation as: PV/nR = T
Plug in our values:
(1.2 atm)(0.170 L)/(0.08206*0.7 moles) = approximately 3.55 Kelvin = T
Answer:
They are used because of preference or convenience, not necessity. These scales came about historically when there were no standards to calibrate a thermometer against. The Fahrenheit scale used the temperature of the coldest thing then known for its zero, which was salty ice.13-Oct-2019
Answer:
4.North to south
Explanation:
In magnetic fields, the north pole is considered negative while the south pole is considered positive. Hence the balloon will be attracted from the north towards the south pole since it is negatively charged.
I think it could be letter B
