answer
When an electron temporarily occupies an energy state greater than its ground state, it is in an excited state. An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light, or collides with a nearby atom or particle
1.1 / 2 = .7 --> 2.86 yrs
.7 / 2 = .45 —> 5.72 yrs
.45 / 2 = .225 —> 8.58 yrs
.225 / 2 = .1125 —> 11.44 yrs
So, for the sample of plutonium to reach .140 mg it should take a little less than 11.44 years.
Hope this helps
Answer:
253.85 L
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
C₃H₈ + 5O₂ —> 3CO₂ + 4H₂O
From the balanced equation above, 4 moles of water vapor were produced.
Finally, we shall determine the volume of the water vapor produced as follow:
Mole water vapor (n) = 4 moles
Pressure (P) = 1 atm
Temperature (T) = 500 °C = 500 °C + 273 = 773 K
Gas constant (R) = 0.821 atm.L/Kmol
Volume (V) =?
PV = nRT
1 × V = 4 ×0.0821 × 773
V = 253.85 L
Thus, the volume of water vapor obtained is 253.85 L
When we say STP that means the system is at its standard temperature and pressure. Both systems is having the same condition hence temperature and pressure is constant. We then set the amount of gas in both cases to be equal. Hence from the ideal gas law,
PV=nRT we can say that with everything constant, volume must also be constant.
The answer is (2) 2 L of methane gas.
Answer: molar mass of H2O2 = 34 g/mol
mass of H2O2 = 68 grams
Explanation:
The decomposition reaction of Hydrogen peroxide (H2O2) is:
2 H2O2 → 2 H2O + O
According to the equation the numbers of moles of H2O2 is 2 moles.
The molar mass of H2O2 = ( 16×2) + (1x2)
32 + 2 = 34 g/mol
∵ atomic mass of oxygen is 16 and hydrogen is 1.
Now, mole=
putting values
2=
mass of H2O2 = 2 × 34 = 68 grams