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:
The answer is
<h2>250 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
volume of object = 25 mL
Density = 10 g/mL
The mass of the object is
mass = 25 × 10
We have the final answer as
<h3>250 g</h3>
Hope this helps you
Answer:
Potassium permanganate.
Explanation:
Both substances are dyes, but the methylene blue has a bigger molecular mass (319.85 g/mol), that means that the particles are bigger in comparison with the potassium permanganate that has a molecular mass of 158.034 g/mol.
Since the molar mass is the half in the case of potassium permanganate, it can be considered that the particle size is the half in size. In the agar, a smaller particle will present less resistance to flow, that means that it going to move faster.
Answer:Benzene typically undergoes reactions in which the aromatic ring is preserved.B. Benzene typically reacts with electrophiles where an aromatic proton is substituted by the electrophile
Explanation:
The reactions of benzene are such that the aromatic ring is not destroyed. Addition reactions destroy the aromatic ring hence they aren't typical reactions of benzene. Benzene rings are attacked by electrophiles in which reaction a proton is substituted by the electrophile. Alkenes only undergo addition reaction and not electrophilic substitution reaction.
Answer:
B. Na
Explanation:
To identify an atom, you simply need to look at the number of protons. This atom has 11 protons. On the periodic table, you can see that the element with 11 protons is sodium (Na).
