Answer:
He developed the concept of concentric electron energy levels
Explanation:
Before Bohr's model, Rutherford's model was proposed. This model explains most of the properties of the atom but failed to explain the stability of the atom.
As per Rutherford's model, electrons revolve around the nucleus in the orbit.
But revolving electron in their orbit around nucleus would give up energy and so gradually move towards the nucleus and therefore, eventually collapse.
Bohr's proposed that the electrons around the nucleus move orbit of fixed energy called "stationary states". Electrons in these stationary states do not radiate energy.
Therefore, proposal of concentric electron energy levels refine the atomic models.
Answer:
you can identify the properties of an element by studying its_____ on the ... between metals and nonmetals on the periodic table are the _____ which have ...
Explanation:
Answer:
A. When two aqueous solutions are mixed, a precipitate is formed.
Explanation:
The precipitate (a solid substance that falls from the liquid) is the result of a chemical reaction taking place between the liquids.
The other three answer choices are indicative of physical changes (temperature change, phase change, color change).
Answer:
pOH=9.9
Explanation:
pH=-log[H+]= -log[0.0000877]
=4.06
pOH+ pH=14
pOH=14-4.06= 9.91
1.1214 mL will a 0.205-mole sample of He occupy at 3.00 atm and 200 K.
<h3>What is an ideal gas equation?</h3>
The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).
Using equation PV=nRT, where n is the moles and R is the gas constant. Then divide the given mass by the number of moles to get molar mass.
Given data:
P= 3.00 atm
V= ?
n=0.205 mole
R= 
T=200 K
Putting value in the given equation:


V= 1.1214 mL
Learn more about the ideal gas here:
brainly.com/question/27691721
#SPJ1