Answer:
75603.86473 K
Explanation:
Given that:
The 1st excited electronic energy level of He atom = 3.13 × 10⁻¹⁸ J
The objective of this question is to estimate the temperature at which the ratio of the population will be 5.0 between the first excited state to the ground state.
The formula for estimating the ratio of population in 1st excited state to the ground state can be computed as:
From the above equation:
Δ E = energy difference = 3.13 × 10⁻¹⁸ J
k = Boltzmann constant = 1.38 × 10⁻²³ J/K
Thus:
T = 75603.86473 K
Answer:
C and D
Explanation:
Atoms with five, six or seven valance electrons gain electrons to complete the octet because it is more convenient for the atoms to gain three, two or one electron as compared to lose five, six or seven electrons. Thus atoms with five, six or seven valance electrons form negative ions by gaining electrons.
Atoms with one, two or three valance electrons lose the electrons to get complete octet because it is more convenient for the atoms to lose one two or three electrons as compared to gain the seven, six or five electrons. The atoms with one, two or three valance electrons form positive ions.
To compare the results when the independent variable is not involved
The reaction between N₂ and F₂ gives Nitrogen trifluoride as the product. The balanced equation is;
N₂ + 3F₂ → 2NF₃
The stoichiometric ratio between N₂ and NF₃ is 1 : 2
Hence,
moles of N₂ / moles of F₂ = 1 / 2
moles of N₂ / 25 mol = 0.5
moles of N₂ = 0.5 x 25 mol = 12.5 mol
Hence N₂ moles needed = 12.5 mol
At STP (273 K and 1 atm) 1 mol of gas = 22.4 L
Hence needed N₂ volume = 22.4 L mol⁻¹ x 12.5 mol
= 280 L
