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:
A) The acceleration due to gravity for any object, including 1 washer on the string, is always assumed to be 10 m/s2.
B) The mass of 3 washers, when converted to kg, is 0.0147 kg.
C) The applied force of 3 washers will increase the applied force on the car to 0.147 N.
Hope i helped. also can i get brainliest
Answer:
Giá trị xà phòng hóa hoặc số xà phòng hóa (SV hoặc SN) biểu thị số miligam kali hydroxit (KOH) hoặc natri hydroxit (NaOH)
<u>Answer:</u> The mass of chlorine needed by the plant per day is 
<u>Explanation:</u>
We are given:
Volume o water treated per day = 25,000,000 gallons
Converting this volume from gallons to liters, we use the conversion factor:
1 gallon = 3.785 L
So, 
Amount of chlorine applied for disinfection = 10 mg/L
Applying unitary method:
For 1 L of water, the amount of chlorine applied is 10 mg
So, for 
of water, the amount of chlorine applied will be 
Hence, the mass of chlorine needed by the plant per day is
From own experience, I know that OsO4 is colorless, but Cr2O3 is actually a solid green from what I have seen. but I guess it could appear yellow-greenish.
