2.26%, 26.8%, 2 2/5, 2.62, 271%
Hope this helps! :D

The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state. The photon energy of the emitted photon is equal to the energy difference between the two states. There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an emission spectrum. Each element's emission spectrum is unique. Therefore, spectroscopy can be used to identify elements in matter of unknown composition. Similarly, the emission spectra of molecules can be used in chemical analysis of substances.
Answer:
the second one filter for dissolved
Explanation:
First we will calculate the number of moles of Iron:

, where n is the number of moles, m is the mass of iron in the reaction and M is the Atomic weight.

moles of Iron.
The same number of moles of Oxygen will take part in the reaction.
So

where 32 is the Atomical Weight of Oxygen (16 x 2).
=>

g
Answer:
The cubic centimeter of boron is 2.
Explanation:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Symbol:
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Given data:
mass of boron = 4.68 g
density of boron = 2.34 g/cm³
volume = ? (cm³)
Solution:
d = m/ v
v = m/d
v = 4.68 g/ 2.34 g /cm³
v = 2 cm³