Answer:
The question has some details missing which I have shown in the attached file.
Explanation:
The concept of arrehenius equation is used to calculate the activation energy.
- Given T1 = 141.0 degree celsius = 414K and K1 = 3.3 x 10^8
- T2 = 77 degree celsius = 350K and k2 = 1.1 x 10^8
- from Arrehenius equation;
- ln(k2/k1) = -Ea/R [1/T2 - 1/T1]
- ln(1.1/3.3) = -Ea/8.314 [ 1/350 - 1/414]
- Ea = 20.679KJ/mol = activation energy for this reaction
Answer:
<em>2.085 x 10^-20 J</em>
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Explanation:
minimum energy required to produce photoelectric effect in chromium is given as hf = 7.21 x 10^-19 J
The work function of chromium Ф = 4.37 eV = 7.00151 x 10^-19 J
The minimum energy required to eject an electron from from a chromium metal E = ?
From E = hf - Ф
substituting values, we have
E = (7.21 x 10^-19) - (7.00151 x 10^-19)
E = <em>2.085 x 10^-20 J</em>
<span>"They have different numbers of neutrons and different mass numbers. Remember mass number is protons plus neutrons. The number of protons for an element will never change, however the number of neutrons can." I took the test, its D</span>
I'm not exactly sure which one but I do know that an acid and a base react in a aqueous solution to form water, so i would probably eliminate the ones that aren't aqueous solutions.
