-
1. Only the identification of potassium requires the blue cobalt glass to see the purple;
2. If it contains both potassium and sodium, it is yellow if it is not seen through the blue cobalt glass, and purple is seen through the blue cobalt glass, because if the cobalt glass is not penetrated, the yellow will cover the purple, and the blue cobalt glass can consider the yellow but cannot filter the purple, so the purple will be seen;
3. As mentioned in the second question, in the flame reaction, the color and light may be masked, and it is also possible to see the color after the superposition of color and light, for example: we know that if the yellow pigment is painted on the white paper and then the black pigment is painted on the white pigment, then the yellow will be masked, but if the red pigment is applied to the yellow pigment, then the pigment will be superimposed into pink
-
First of all, you need to know how the flame color reaction works.
The outer shell electrons are stripped of sodium during combustion, right, it will absorb photons of a certain frequency (I don't know one, several), then it will show the color of the wavelength band that is not absorbed, that is, yellow light, which is also a mixed color. In the same way, pure potassium must be absorbed differently from sodium, which is purple. The spectral drop point is different.
Your first question: "all applications" is not right, different elements have different flame colors, cobalt glass can only absorb yellow light, through blue-violet light.
The second: I'm not sure, I haven't seen the K element flame color yellow, maybe, there should be no really pure potassium, more or less mixed with sodium, the flame color is yellow is normal, but it doesn't mean that the characteristic flame color of potassium is yellow, is it acceptable? (If the question is asked, it should be asked why, then it should be that there is no cobalt glass).
Thirdly, considering the flame color of the mixed elements, you can refer to the principle I mentioned above to see what color light is absorbed by the various elements, and then the opposite color is presented. Sodium and potassium are generally mixed, and the purple color will be covered by the yellow light of sodium, and people's color vision perception ability is different, so the yellow light should be filtered with blue cobalt glass.
Suggestion: Take a look at the light dispersion section of the physics book...
-
1No, only potassium.
2 That is what he said falsely, that the flame color of potassium is purple, and that it cannot be said to be yellow because it is not purple.
3 will turn yellow. It's like not using blue cobalt glass to see the flame reaction of potassium, because purple is masked when yellow and purple are together. It's not a problem with the elements, it's a problem with the color itself.
-
1. Potassium is required to see purple through blue cobalt glass.
2. The flame color reaction of the K element is purple, and it is known that all K elements contain a certain amount of Na elements, and some people say that the flame color of K elements is yellow. The na element does not necessarily contain the k element. I was also confused about this question at the time, and I asked the teacher.
3, yellow; Purple can only be seen through blue cobalt glass. It depends on the two elements after the flame color is mixed, which is a physical thing.
Note: The flame color reaction is a physical change.
-
Contains sodium element na yellow.
Contains lithium element li purple red.
Contains potassium element k light violet (seen through blue cobalt glass, because potassium is often mixed with sodium, yellow masks light purple).
Contains rubidium element RB violet.
Contains calcium, ca, brick red.
Contains strontium SR magenta.
Cu-green with copper elements.
Contains barium element BA yellow-green.
Contains cobalt element CO light blue.
Note: Iron-containing elements Fe are colorless).
-
Hello, I will answer for you about what spectrum is the flame color reaction, the flame color reaction I believe many friends still don't know, now let's take a look! 1. When alkali metals and their salts are burned on a flame. <>
1. When the alkali metal and its salts are burned on the flame, the electrons in the atom absorb the energy and jump from the orbital with lower energy to the orbital with higher energy, but the electrons in the orbital with higher energy are unstable and quickly jump back to the orbital with lower energy, and then the excess energy is released in the form of light.
2. The wavelength of the emitted light is in the visible range (wavelength is 400nm 760nm), so it can make the flame show color.
3. However, due to the different atomic structures of alkali metals, the change of energy during the electron transition is not the same, and different wavelengths of light are emitted. The spectrum of each element has some characteristic spectral lines, which emit a characteristic color to color the flame, and the presence of a certain element can be judged according to the flame color. For example, flame magenta contains strontium, flame jade green contains copper, flame yellow contains sodium, etc.
4. Neon principle: When the external power supply circuit is turned on, the output of the transformer will generate a high voltage of thousands of volts or even tens of thousands of volts.
5. When this high voltage is applied to the electrodes at both ends of the neon tube, the charged particles in the neon tube are accelerated in the high-voltage electric field and fly to the electrode, which can excite and produce a large number of electrons.
6. These excited electrons are accelerated in a high-voltage electric field and collide with the gas atoms in the lamp.
7. When these electrons collide with the energy of the free gas atoms is large enough, the gas atoms can be ionized and become positive ions and electrons, which is the ionization phenomenon of gas.
8. The collision between charged particles and gas atoms emits excess energy in the form of photons, which completes the whole process of lighting up the neon sign.
-
Not a chemical change. The reaction does not meet the basic requirements for chemical change: there is the formation of a new substance. Its essence is the change in energy caused by the transition of electrons.
-
The flame reaction is a physical reaction, not a chemical reaction.
-
That's right.
The various visible light released in the flame color reaction is essentially due to the high temperature of the heat source, and the energy of the metal ions that do the flame color reaction rises after being heated.
High, excited electron transitions, the energy difference between energy levels is released in the form of visible light, and no new matter is generated in this process, only.
It is a transition of electrons and should belong to the physical change.
Therefore, although it is called a flame color reaction, it is not actually a chemical change, but a physical change.
The flame color reaction is a reaction in which certain metals or their volatile compounds take on the characteristic color of a flame when it burns in a colorless flame. Some metals, or their compounds, can give a special color to the flame when burned. >>>More
The main purpose of observing with blue cobalt glass is to exclude the interference of sodium, that is, to exclude yellow, for other color interference, because in general, most of the impurities contained in potassium and potassium-containing compounds are substances containing sodium, and only a small part are other elements, so their influence is not considered.
The flame reaction is an elemental property. It is a light phenomenon caused by the jump of electrons in an atom. >>>More
When the peripheral electrons of metal ions or atoms are heated, they gain energy, so that the electrons are excited from the low-energy orbital to the high-energy orbital, and these electrons in the high-energy orbital are extremely unstable and instantly return to the low-energy orbital. During this "fallback", the electrons release energy, usually in the form of light energy, thus showing different flame colors. >>>More
Maybe you've had the experience of accidentally spilling miso soup in the oven, and the burning flame will instantly turn yellow. This is because miso soup contains table salt. >>>More