Answer:
12.50g
Explanation:
T½ = 2.5years
No = 100g
N = ?
Time (T) = 7.5 years
To solve this question, we'll have to find the disintegration constant λ first
T½ = In2 / λ
T½ = 0.693 / λ
λ = 0.693 / 2.5
λ = 0.2772
In(N/No) = -λt
N = No* e^-λt
N = 100 * e^-(0.2772*7.5)
N = 100*e^-2.079
N = 100 * 0.125
N = 12.50g
The sample remaining after 7.5 years is 12.50g
Answer:
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Explanation:
Answer: Volume of gas in the stomach, V = 0.0318L or 31.8mL
Explanation:
The number of moles of oxygen will remain constant even though the liquid oxygen will undergo a change of state to gaseous inside the person's stomach due to an increase in temperature.
<em>Number of moles of oxygen gas = mass/molar mass</em>
molar mass of oxygen gas = 32 g/mol
mass of oxygen gas = density * volume
mass of oxygen gas = 1.149 g/ml * 0.035 ml
mass of oxygen gas = 0.040215 g
Number of moles of oxygen gas = 0.0402 g/(32 g/mol)
Number of moles of oxygen gas = 0.00125 moles
<em>Using the ideal gas equation, PV=nRT</em>
where P = 1.0 atm, V = ?, n = 0.00125 moles, R = 0.082 L*atm/K*mol, T = (37 + 273)K = 310 K
<em>V = nRT/P</em>
V = (0.00125moles) * (0.082 L*atm/K*mol) * (310 K) / 1 atm
V = 0.0318L or 31.8mL
Protons and neutrons are located in the nucleus of the atom while the electrons move in the trajectory of the shell
<h3>Further explanation
</h3>
Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Isotopes of Helium : helium-3 and helium-4
protons = 2
electrons=protons=2
neutron=mass number-atomic number=3-2=1
protons = 2
electrons=protons=2
neutron=mass number-atomic number=3-2=1
protons = 2
electrons=protons=2
neutron=mass number-atomic number=4-2=2
Protons and neutron in the nucleus, electrons in the shell
