The symbolic expression and reaction phenomenon of the chemical reaction of carbon dioxide into clarified lime water are obtained

The symbolic expression and reaction phenomenon of the chemical reaction of carbon dioxide into clarified lime water are obtained

1. When a small amount of CO2 is introduced, the clarified limewater becomes turbid and white precipitates are formed
CO2+Ca(OH)2==CaCO3↓+H2O
2. Continue to inject CO2 until excess, the white precipitate disappears, and the turbid liquid becomes clear again
CaCO3+H2O+CO2==Ca(HCO3)2

Literal expression and chemical symbol expression of hydrogen combustion and basic types of reaction
It's urgent

Hydrogen burns in oxygen to produce water
2h2 + O2 = ignition = 2H2O
Chemical reaction

Expression of chemical symbol for potassium chlorate
Potassium permanganate is a dark purple solid. When it is heated, it will decompose into oxygen. At the same time, potassium permanganate and manganese dioxide will be formed. What is its symbolic expression

2kmno4 = = heating = = k2mno4 + MnO2 + O2 ↑
This is the result of the decomposition of potassium permanganate
2kclo3 = = heating / catalyst = = 2KCL + 3O2 ↑
This is the result of the decomposition of potassium chlorate
You can send me a message if you don't understand

A problem of special relativity!
Does the mass energy equation E = MC only calculate the released energy after the object disappears? Is there no energy when the object is still? What is the static energy E0 = M0 * C
And what does relativistic kinetic energy mean? Why does kinetic energy equal to e = mc-m0 * C?
It's better to have specific examples and exercises!

The connotation of the mass energy equation is that the essence of mass is energy. The change of mass must be accompanied by the absorption or release of energy. When a body is still, it has mass because it has static energy. This kind of energy is contained in the interaction potential energy of various micro particles. Whether it is still or moving, energy is equal to the product of mass and the square of light speed

On special relativity
A distant star leaves us at the speed of 0.8C. According to the clock of the earth's inertial system, the flash it radiates varies in a cycle of 5 days and nights. According to the reference frame fixed on this star, the flash cycle is?
What is the way to analyze this type of problem?

Detailed analysis and solution are as follows, see the figure below
 
 
The speed is equal. The speed of the earth looking at the planet is 0.8C, and the speed of the planet looking at the earth is also 0.8C
T is the flash cycle seen by the earth. No matter where the first flash is, the second flash always adds t time to the time of the first flash
The second flash is more l distance than the first one, and this distance is exactly the distance that the planet is far away in five days and nights. Therefore, the second flash is later than the first flash. This distance is divided by the speed of light
So the actual flash period measured on earth is the period seen minus the time taken for light to travel the extra distance
 
That is T-L / C = t-0.8t = 0.2T, that is to say, the period seen on the earth is converted into the period of flash, which is 0.2T
The period measured on the planet is: 0.2T √ (1-0.8 & # 178;) = 0.12T = 14 hours and 24 minutes

On special relativity
Both a and B were born at the same time. Their life span was 80 years. They all moved at the speed of 0.745c
When a sees that he is 60, how old does he see B? Why?

The problem is not rigorous, it should be ab born at the same time and in the same place
A seems to be younger than B, root (1-vv / CC) * 60 = 40

On special relativity
When two things happen in a certain place, the time interval between a and a is 4S. If the time interval between B and a is 5S, what is the velocity of B relative to a?
The process of solving the problem is more detailed. What is the solution idea and formula for this kind of problem?

γ = 1 / root (1-V ^ 2 / C ^ 2) from △ t '= γ △ t (where △ t is the inherent time), then 5 = γ 4, v = 3C / 5

Some problems about special relativity
I don't know anything about relativity
In the theory of relativity, there are clock slow effect and ruler contraction effect, but I also see that whether time becomes faster or slower depends on whether the object is far away from the observer or close to the observer
That's what happened in the adventures of Mr. Tompkins
There's the twin paradox. I haven't understood it for so long

As for the twin paradox, the clock slow effect of two inertial frames is mutual. That is to say, in the process of motion, a finds B slow, B finds a slow

What unit is ut in physics,

You know μ T, micro Tesla, which is the minus sixth Tesla of ten

Cfop magic cube formula
How can I not understand that tutorial? From C to F, I can't connect cross. Is it to make one side cross, and then the other side of cross edge block has the same color as the center block? But in F, how can the corner block be aligned and the four colors of the two sides are aligned? How can this be spelled out?

First of all, you misunderstood the first step of cross,
The following article is without the original picture. The method of building Rubik's cube cross is actually a cross, and the order of them is as follows: Cross (bottom cross), F2L (first two layers), oll (upper layer inversion), PLL (upper layer restoration). This method is the most popular fast restoration method today. The completion method is divided into four steps: cross - > F2L - > oll - > PLL Cross: select one side as the bottom layer first, Set up the cross. F2L: first two layer means to restore the bottom and middle layers of the cross at the same time. The color of the upper layer of oll: Orient last layer is the same, regardless of whether the position is correct. The edges and corners of the upper layer of PLL: position last layer are correctly positioned. 1. Set up a complete cross as shown in the figure. This is the goal we want to achieve in this step, 1.1.1 to understand the color of your cube, please pick up your cube and see what colors are on the six sides of your cube. If your cube has been disrupted, then look at the colors of the six central blocks of the cube (regardless of corner and edge blocks), for example, Here is my magic cube. Note: the color of the face is always the same as that of the center block. The color of the center block and the face contains two layers: 1. What color is it; 2. The arrangement of colors. The first point is like the magic cube above, The colors of the six sides (center block) are yellow, orange, green, red, blue and white. The second point is about how the six colors are arranged, such as what color is the four sides next to yellow, what color is the four sides next to orange, and so on, We can go to the next step. 1.1.2 to choose the color of the starting surface and the memory cube, we should first choose a certain color of the cube as our "starting surface", that is, every restoration cube in the future starts from this color surface. This method is very meaningful for quickly improving the restoration speed, Beginners can also become proficient quickly. You can fix a starting surface according to your own color perception. It is recommended not to use dark colors, namely red and blue. Another point is that this starting surface can be changed. If you feel that it is better to restore from another color in the future, you can change it again. Next, you need to remember the color of the cube simply, You need to remember: what's the color and order of the four sides next to the beginning face? Here's an example of my previous learning process to explain the content and method of memory, I use the Yellow starting surface: 1. Remember that the clockwise order of the four colors (starting from orange) is "orange → cyan → red → blue". 2. Remember that the back of orange is red (orange red is a similar color system); 3. Remember that the back of cyan is blue (cyan blue is a similar color system); the first memory content here actually contains the content of 2 and 3 points, Note: the color matching of each side of the standard cube is generally fixed. The current popular color matching order is red back to orange, blue back to cyan, and yellow back to white. That is to say, the Rubik's cube in the above figure, often referred to as "standard cube color", also refers to this. 1.1.3 in principle, the order of the four edges has no requirement to restore the order, But beginners don't have a deep memory of colors. They can use the following order: 1. Restore any edge first; 2. Restore another edge which is in the back relationship with the first edge; 3. Restore any one of the remaining two edges; 4. Restore the last edge; just take an example to illustrate: the first step in the order of erecting edges is to restore any edge, Here, we choose to restore the "yellow orange" edge first; the second step is to restore the "yellow red" edge which is in the back relationship with the "yellow orange" edge, presenting a "one" on the magic cube; the third step is to restore any one of the remaining two edges, here we choose to restore the "yellow green" edge, according to the color order of "orange → green → red → blue", The fourth step is to restore the last edge to the last position. Thus, the main body of the cross is completed. The first edge of the 1.1.4 frame starts from this step, We've officially started to learn how to restore the magic cube. There are four possibilities for the restoration of the first edge: r r r 2 RF r F. in this paper, we list all kinds of states in detail, but we are not required to memorize them one by one. Please practice more and understand the rules slowly. In fact, the whole restoration of the first layer can be summarized into several rules, In the whole restoration process here and below, except for the restored blocks and the blocks to be restored now, all the other center blocks, corner blocks and edge blocks do not need to pay attention to their situation, Even if they are already in the right position. 1.1.5 the second edge first makes the following rotation adjustment to your cube. 1.1.5 the second edge first makes the following rotation adjustment to your cube. After rotation, observe the position relationship between the second edge and the first edge, and rotate several times until the relationship between the second edge and the first edge becomes one of the following states, Here's how to restore the second edge. R r'r2 ruf'r'uf'fr b'r'fuf'b'u'b1.1.6 the third edge is the same as the second edge. First, make the same rotation adjustment to your magic cube. After rotation, observe the position relationship between the third edge and the first two edges. Turn several times until the relationship between the third edge and the first two edges becomes one of the following states, The following is the way to restore the third edge. The fourth edge of F'f F2 f'u'rfu'r b'ur'b2d2f21.1.7 is the same as the previous method. First, rotate and adjust your Rubik's cube. After rotating, observe the position relationship between the fourth edge and the front three edges. Rotate several times until the relationship between the fourth edge and the front three edges becomes one of the following states, Here's how to restore the fourth edge. The last step of F f'f2 f'u'r fu'r1.1.8 aligning the center block is to align the center block, or make the following rotation adjustment to your magic cube. D after rotation, observe the color alignment of the four edge blocks and the center block on each side. After several turns, a complete cross will appear