Answer: According to the Bohr model, atoms emit light because excited electrons are returning to lower energy states, emitting the energy difference. This energy always has a specific wavelength because the electrons can only exist in set orbits. ... An emission spectrum is the frequencies of light emitted from an atom.
Explanation:
The following are scientific observations which led to development and changes of periodic table: Dmitri Mendeleev is the first periodic table organized 63 known element according to its properties, organized into rows and columns and inscribed name, mass and chemical properties on each element. Julius Lothar Meyer who independently worked in Germany with Ernest Rutherford. They experimented with 38 metals and found out that the positive charge of each element nucleus increased by one from element to element and organized the periodic table that tip to modern explanation of atomic number and the recognition of atomic number was the basis for organization of periodic table.
A=acid
B=it say neither it say it’s alkaline
C=acid
D= it say neither it say it’s alkaline
As the atomic mass of iron is 55.847u
We say that it is the mass of one mole of iron.
By formula it can be find by
No.of mole=mass in g/molar mass
Mass in gram = no.of mole x molar mass
No.of mole =1
Molar mass = 55.847g
Mass in gram = 1x55.847
= 55.847g of Fe
Uranium is in the "f" block, because it's external electron configuration is
