Answer:
In Beryllium there are two energy levels
Explanation:
Answer: The energy of the 4-s subshell is lower than the energy of 3-d subshell.
Explanation:
During the filling of electrons in subshells, the lower energy levels are filled before the higher energy levels. Also known as Aufbau principle.
Energy of the sublevel = (n + l)
where : n = Principal quantum number
l = Azimuthal quantum number(s=0,p=1,d=2,f=3)
Energy of 4-s subshell= (4+0) = 4
Energy of 3-d subshell=(3+2) = 5
Energy of 4-s subshell is lower than the energy of 3-d subshell, that is why 4s orbital is filled before the 3-d subshell.
An atomic mass unit is defined as precisely 1/12 the mass of an atom of carbon-12.
Answer:first D. 88L
Second A 2*10^24
Explanation:
At stp 1 mole = 22.4L
mw Cl2= 70.9
280 g =280/70.9 moles, about 4
4*22.4 = about 88
aw Sr 87.6 —> 6.02214076*10^23 atoms = 1 mole
The rate of the backward reaction increases
Explanation:
It is evident that if the reaction is left to proceed spontaneously, the forward reaction is favored because it results in a decrease in pressure in the system (The total reactants have 5 moles and the products have 3 in total).
Increasing H₂O concentration is then reaction, therefore, stymies the forward reaction and favors the reserves reaction. This is because the reverse reaction will lead to reduced pressure.
