Answer:
2.1x10⁹ years
Explanation:
U-238 is a radioactive substance, which decays in radioactive particles. It means that this substance will lose mass, and will form another compound, the Pb-206.
The time need for a compound loses half of its mass is called half-life, and knowing the initial mass (mi) and the final mass (m) the number of half-lives passed (n) can be found by:
m = mi/2ⁿ
The mass of Pb-206 will be the mass that was lost by U-238, so it will be mi - m. Thus, the mass ration can be expressed as:
(mi-m)/m = 0.337/1
mi - m = 0.337m
mi = 1.337m
Substituing mi in the expression of half-life:
m = 1.337m/2ⁿ
2ⁿ = 1.337m/m
2ⁿ = 1.337
ln(2ⁿ) = ln(1.337)
n*ln(2) = ln(1.337)
n = ln(1.337)/ln2
n = 0.4190
The time passed (t), or the age of the sample, is the half-life time multiplied by n:
t = 4.5x10⁹ * 0.4190
t = 1.88x10⁹ ≅ 2.1x10⁹ years
Balance the equation to find the answer. The easiest place to start is with the C’s and H’s since they only appear once on both sides of the equation:
C4H8 + 6O2 —> 4CO2 + 4H2O
The O2 has already been balanced for us (but normally you would add the number of O’s on the right after balancing C’s and H’s and use that to balance the O’s on the left).
As you can see you get 4 molecules of CO2 and 4 of H2O.
Answer:
Helium can be liquefied, but its condensation temperature is the lowest among all the known substances. Helium has many unique properties: low boiling point, low density, low solubility, high thermal conductivity and inertness, so it is use for any application which can explioit these properties.
Explanation:
Sorry if its to long (I could maybe shorten it if needed)
Answer:
I cant really see the individual problems very well but i hope this helps
Explanation:
Decomposition = one thing -> 2 or more things
Synthesis= 2 or more things -> 1 thing