Answer:
See explanation below
Explanation:
3. Each atom has unique electron energy level when compared to other, when electron relaxes from an excited energy level, it emits energy in the form of electromagnetic waves with energy equals to the difference between energy of ground and excited state. As electromagnetic wave wavelength obeys planck relation

And the energy of each photon in electromangetic wave of specific frequency is

Where h is planck's constant
We can see that the wavelength, which determines color and position of bright line in spectroscope corresponds directly to the energy of electromagnetic wave, and thus, the characteristic energy of atom.
4. From the answer above, you now know that electronic transition can emit electron with specific wavelength. In strontium, emission of colored light occurs by the relaxation of electrons in excited state such that the difference between excited energy level and ground level falls in the energy of visible light spectral range.
5. In Na, ground state configuration is 2-8-1. 2-7-1-1 indicates that one of electron in ground state got excited by external energy to excited state, and thus, indicates that Na atom is in excited state
Answer:
8.085x10²¹ atoms
Explanation:
Atomic mass of Fe = 55.845 g/mol
it means ,
1 mole Fe = 55.845 g
1 mole = 6.02x10²³ atoms
so,
55.845g Fe has = 6.02x10²³ atoms
∴0.750 g Fe has = {(6.02x10²³ x 0.750)/55.84} atoms
=8.085x10²¹ atoms
It can form long chains, unlike any other element
It is found in every life-related chemical
Looking at the formula, each mol of P4O10 contains 4 mol of P, so
(58.5 mol P4O10) x (4 mol P/ 1 mol P4O10) = 234 mol
The answer is B! Chromatography involves solvent separation on a solid medium. Distillation takes advantage of differences in boiling points. Evaporation removes a liquid from a solution to leave a solid material