Answer: Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus.
so C would seems to be right.
Explanation: The energy of an electron depends on the size of the orbit and is lower for smaller orbits. Radiation can occur only when the electron jumps from one orbit to another. The atom will be completely stable in the state with the smallest orbit, since there is no orbit of lower energy into which the electron can jump.
Molality is one way of expressing concentration for solutions. It has units of moles of solute per kg of solvent. From the given values, we easily calculate for the moles of solute by multiplying the mass of solvent to the molality. We do as follows:
moles solute = 0.3 (10) = 3 mol solute
Answer:
The answer is "10.84 g".
Explanation:
The formula for calculating the number for moles:

In the given acid nitric:
Owing to the nitric acid mass = 
Nitric acid molar weight
If they put values above the formula, they receive:


In the given chemical equation:

In this reaction, 2 mols of nitric acid are produced by 1 mole of water.
So, 1.204 moles of nitric acid will be produced:

We are now using Equation 1 in determining the quantity of water:
Water moles 
Water weight molar 


B. 8
Although it may seem that transition metals would have more than 8 valence electrons, they in fact do not.