Answer:
269.068 kJ/mol.
Explanation:
<em>ln (k₂/k₁) = (Eₐ/R) [(T₂ - T₁)/(T₁T₂)].</em>
<em>k₁ = 6.20 x 10⁻⁴ min⁻¹, T₁ = 700.0 K.</em>
<u><em>To get k₂:</em></u>
in first order reactions: k = 0.693/(half-life).
∴ k₂ = 0.693/(29.0 min) = 2.39 x 10⁻² min⁻¹, T₂ = 760.0 K.
∵ ln (k₂/k₁) = (Eₐ/R) [(T₂ - T₁)/(T₁T₂)]
∴ ln [(2.39 x 10⁻² min⁻¹)/(6.20 x 10⁻⁴ min⁻¹)] = (Eₐ/(8.314 J/mol.K)) [(760.0 K - 700.0 K) / (760.0 K)(700.0 K)].
3.65 = (Eₐ/(8.314 J/mol.K)) (1.128 x 10⁻⁴).
<em>∴ Eₐ =</em> (3.65)(8.314 J/mol.K) / (1.128 x 10⁻⁴) = <em>269.068 kJ/mol.</em>
Protons= 88
Neutrons= 138.
The weight of an element is comprised of entirely protons and neutrons. To get the protons look at the atomic number on the periodic table (88) and those are your protons. To get the neutrons take the weight of the isotope that you have and subtract the protons, giving you 138.
Answer:
2.52kg
Explanation:
80mm = 8 cm
0.15m = 15 cm
volume of the container = 10m × 8cm × 15cm
= 1200 cubic centimetres
mass = density × volume
= 2.1 × 1200
= 2520g
2520/ 1000
= 2.52kilograms
Answer:
Paired = 12
Unpaired = 0
Explanation:
Magnesium is alkaline earth metal.
It is present in second group.
Its atomic number is 12 and atomic mass 24 amu.
Electronic configuration:
Mg₁₂ = 1s² 2s² 2p⁶ 3s²
It can seen from electronic configuration that all electrons are paired because s subshell have one orbital and it can accomodate two electrons. Each s subshells in magnesium have two electrons so these are filled and have paired electrons. While p subshell have three orbitals and can accomodate six electrons two by each orbital with opposite spin thus 2p is also filled and have paired electrons.