What is the symbolic expression for testing the chemical reaction of carbon dioxide with clarified lime water

What is the symbolic expression for testing the chemical reaction of carbon dioxide with clarified lime water

CO2 + Ca (OH) 2 = H2O + CaCO3 (precipitation)

Write chemical symbol expression. There is decomposition reaction of water formation
It's a decomposition reaction!

There are a lot of reactions like this
2nahco3 = = heating = = Na2CO3 + CO2 + H2O
2h2o2 = = heating = = 2H2O + O2
CuSO4.5H2O = = heating = = CuSO4 + 5H2O
wait

Chemical symbol expression

1、 He, NE, AR, krypton, Xe, RN, Au, Ag, Cu, Fe, Al, CA, Na, K, C, P, s, Si, B, as, H2, O2, N2, F2, CL

The answers to the mental arithmetic problem card of grade 5 Volume 2
1 to 140 pages is the best

A complete collection of oral math problems in grade four of primary school

The fourth grade oral arithmetic exercises (1) 200 × 30 = 2) 42 × 4 = 3) 63 × 7 = 4) 230 × 20 - 46 = 5) 130 × 3 = 6) 60 × 50 = 7) 36 × 20 = 8) 490 △ 70 + 58 = 9) 150 △ 3 = 10

Mathematical oral problems
3.14*0.6*1.4*20=
The height of a cylinder is 5m, the diameter is 0.2m, and the surface area of the cylinder is calculated

3.14*0.6*1.4*20=52.752
2)
The radius is 0.2 △ 2 = 0.1 (m)
Surface area = 0.1 * 0.1 * 3.14 * 2 + 0.2 * 3.14 * 5
=0.0628+3.14
=3.2028(m^2)

What is the main content of space-time view of special relativity put forward by Einstein?

Special relativity is a theory based on the four-dimensional space-time view. To understand the content of relativity, we need to have a general understanding of the space-time view of relativity. In mathematics, there are various multi-dimensional spaces, but so far, the physical world we know is only four-dimensional, that is, three-dimensional space plus one-dimensional time, Let's not discuss it here. The four-dimensional space-time of x0d is the lowest dimension of the real world. Our world happens to be four-dimensional. As for the high-dimensional real space, at least now we can't perceive it. A ruler rotates in three-dimensional space (excluding time), its length remains unchanged, but when it rotates, its coordinate values change, The meaning of the four-dimensional space-time is that time is the fourth dimensional coordinate, which is related to the spatial coordinate. That is to say, space-time is a unified and indivisible whole, and they are a relationship of "one ebb and the other". The four-dimensional space-time is not limited to this. According to the relationship between mass and energy, mass and energy are actually the same thing, and mass (or energy) are not independent, In four-dimensional space-time, mass (or energy) is actually the fourth dimensional component of four-dimensional momentum, momentum is the quantity describing the motion of matter, so it is natural that mass is related to the state of motion, In addition, four-dimensional velocity, four-dimensional acceleration, four-dimensional force and four-dimensional form of electromagnetic field equations are defined in four-dimensional space-time. It is worth mentioning that the four-dimensional form of electromagnetic field equations is more perfect, which completely unifies electricity and magnetism. Electric field and magnetic field are described by a unified electromagnetic field tensor. The physical laws of four-dimensional space-time are much more perfect than three-dimensional laws, This shows that our world is indeed four-dimensional. It can be said that at least it is much more perfect than Newtonian mechanics. At least because of its perfection, we can't doubt it. In the theory of relativity, time and space form an inseparable whole - four-dimensional space-time, Energy and momentum also form an inseparable whole - four-dimensional momentum. This shows that there may be a deep connection between some seemingly unrelated quantities in nature. When we discuss general relativity in the future, we will see that there is also a deep connection between space-time and the four vectors of energy and momentum, In other words, motion must have a reference, which is the reference system. Galileo once pointed out that the motion of a moving ship can not be distinguished from that of a stationary ship, that is to say, the motion of a moving ship can not be described in isolation, When you are in a closed cabin and completely isolated from the outside world, even if you have the most developed mind and the most advanced instruments, you can't perceive whether your ship is moving at a constant speed or at rest. What's more, you can't perceive the speed because there is no reference. For example, we don't know the overall motion state of our universe, because the universe is closed, As the first basic principle of special relativity: the principle of special relativity. Its content is: inertial frames are completely equivalent and indistinguishable. The famous Michelson Morey experiment completely negates the ether theory of light, and draws the conclusion that light has nothing to do with the reference frame. That is to say, whether you are standing on the ground or on a running train, The measured speed of light is the same. This is the second basic principle of special relativity, the principle of invariable speed of light. From these two basic principles, we can directly deduce all the contents of special relativity, such as the coordinate transformation and speed transformation of relativity. For example, the change of speed is contrary to the traditional law, but it is proved to be correct in practice, for example, the speed of a train is 10m / s, The speed of a person in the car relative to the car is also 10m / s. people on the ground see that the speed of a person in the car is not 20m / s, but about (20-10 ^ (- 15)) m / S. in general, this relativistic effect can be completely ignored, but when approaching the speed of light, this effect increases significantly. For example, the speed of a train is 0.99 times the speed of light, and the speed of a person is 0.99 times the speed of light, So the ground observer's conclusion is not 1.98 times the speed of light, but 0.999949 times the speed of light. The person in the car sees that the light coming from behind does not slow down, which is also the speed of light for him. Therefore, in this sense, the speed of light cannot be surpassed, because no matter in that reference frame, the speed of light is constant. The speed transformation has been proved impeccable by numerous experiments in particle physics

A topic about special relativity
If a "car" with wheel radius r moves in a straight line relative to the ground at a constant speed V close to the speed of light, what is the shape of the car wheel seen by an observer who is stationary relative to the ground? Please prove it

According to the relativistic effect, the horizontal diameter of the wheel along the V direction will be shortened while the vertical diameter will not be changed. Therefore, in the view of the ground observer, the wheel is elliptical. We can take the car as the s' coordinate system. In this reference system, the equation of the wheel circumference is x'2 + y'2 = R2. In the view of the ground observer, we can list a standard equation of the ellipse,

Einstein put forward special relativity in 1905. The starting point of special relativity is based on two basic hypotheses, which are ()
A. The absoluteness of simultaneity and the relativity of simultaneity B. the moving clock slows down and the moving ruler shortens C. the absoluteness of time interval and the absoluteness of space distance D. the principle of relativity and the principle of invariable speed of light

Einstein put forward two basic hypotheses for Relativity: Relativity and the principle of invariable speed of light; other contents are based on these two points; so D

The two basic hypotheses of Einstein's special theory of relativity are

Principle of relativity in narrow sense: the law of nature has the same mathematical form in all inertial reference frames
Principle of invariable speed of light: the speed of vacuum light is the same in all inertial reference frames