Where does most of the mass of the universe come from? In ordinary matter, most of the mass is contained in atoms, and the majority of the mass of an atom resides in the nucleus, made of protons and neutrons. Protons and neutrons are each made of three quarks.
Long wave I think is the correct answer
Zeff is the effective nuclear charge wherein, Z resembles the number of protons in the nucleus while S corresponds to the number of non-valence electrons.
Zeff = Z - S
Silicon has 14 protons; its electron configuration is [Ne] 3s2 3p2. Its
non-valence electrons is in the n = 1 and n =2 shells. There are 2
electrons in n = 1 and 8 in n = 2, so there are a total of 10
non-valence electron.
<span><span>Z<span>eff</span></span>= 14−10= 4</span>
So, the answer is 4.
I believe the answer is C) there is an obvious reasoning for this all you have to do is eliminate answers that don't seem right for example, A)the plates are all moving the same direction every plate moves in different directions. B) The plates are all the same size. Well, it's really obvious that that is not true because every plate has its different shape and size. D) where two plates meet, they always move apart. If this were true, then we would never have earthquakes when plates meet earthquakes happen. so there for the answer is C)
<span>Answer
is: activation energy of this reaction is 212,01975 kJ/mol.
Arrhenius equation: ln(k</span>₁/k₂) = Ea/R (1/T₂ - 1/T₁<span>).
k</span>₁<span> = 0,000643
1/s.
k</span>₂ = 0,00828
1/s.
T₁ = 622 K.
T₂ = 666 K.
R = 8,3145 J/Kmol.
1/T₁<span> = 1/622 K = 0,0016 1/K.
1/T</span>₂<span> = 1/666 K =
0,0015 1/K.
ln(0,000643/0,00828) = Ea/8,3145 J/Kmol · (-0,0001 1/K).
-2,55 = Ea/8,3145 J/Kmol · (-0,0001 1/K).
Ea = 212019,75 J/mol = 212,01975 kJ/mol.</span>