Urgent, I asked in computer class, chemical science questions

The valence should be the valency.

Generally speaking, atoms combine with atoms to form a stable structure (the outermost electron number is 8), and the gain and loss of electrons is the process of matter formation. The gain and loss of electrons is demarcated by the number of outermost electrons being four, and it is easier to get electrons when the number of outermost electrons is greater than four, so the valency sign is negative, and the magnitude is equal to the number of electrons obtained; When the number of electrons in the outermost shell is less than four, it is easier to lose electrons, so the sign is positive, and the magnitude is also equal to the number of electrons lost.

Generally speaking, the valency of each element is not unique, you should be in the third year of junior high school, just remember the book, chemistry is actually not difficult.

When elements are combined with each other, the ratio of their atoms has a definite value. The number of atoms of an element that combine with each other is called the valency of that element.

The valence of common elements slips smoothly (1).

potassium, sodium, hydrogen and silver are monovalent, calcium, magnesium, zinc, barium are bivalent;

Chlorochlorobromoiodine is negative monovalent, usually oxygen is negative bivalent;

Copper is one and two aluminum.

1. Valence When the elements are combined with each other, the ratio of the number of atoms has a definite value. The number of atoms of an element that are combined with each other is called the valency of this element Common element valency (1) Potassium, sodium, hydrogen, silver, positive bivalent, calcium, magnesium, zinc, barium, positive bivalent; Chlorochlorobromoiodine is negative monovalent, usually oxygen is negative bivalent; Copper is one and two and aluminum is three, and iron has two and three; Carbon has positive two and positive four, and sulfur has negative two positive four and positive six. Common elemental valence (2) monovalent hydrochloride, lithium potassium, sodium silver, divalent magnesium oxide, calcium, barium, zinc, copper, mercury, 12iron, 23, carbon, tin, lead, 24, sulfur, minus 2, 46, minus 3 to 5, nitrogen and phosphorus, halogen negative.

One, one, three, five, seven, trivalent remember boron, aluminum, gold. The valence of common elements (3) positive lithium, sodium, potassium, hydrogen silver, n-dimagnesium, calcium, strontium, barium, zinc; The negative monovalent is chlorine, bromine, 、......

Three, iron has positive two and positive three;

I would like to ask how many G are important things in the E disk?

There may be a physical bad sector in the E drive, and you don't mean that you have to change the hard drive, you can format the E drive.

Then use the "Easy Data Recovery Wizard" to help you recover the data of the E disk, formatted, it is possible to repair some hard disk bad sectors, if there is nothing important in other disks, you had better format the whole disk, use the power efficiency source hard disk repair tool to repair the bad sectors of the hard disk, and then repartition, so that the hard disk can continue to be used.

HP's after-sales service is still good, if the warranty period is not over, go and change a hard disk for free, although the exchange is not brand new, but it is okay to use, I have changed it twice.

It's a problem with the hard disk, but there are hard bad sectors on the hard disk, you shouldn't try to fix it, that will expand the scope of the bad sectors, you should use data recovery software to recover the data first, and then change the hard disk, or simply use PQ to hide the E partition.

It may be that your computer's system has too much junk.

Scan the junk with the computer's built-in one-click junk removal tool.

Here's how:

Start --- all programs --- impact personnel tool --- one-click clearing!! It's okay if you don't have this tool.

Just go and search for one online.

One reason is that it is possible that you are operating at the time of normal operation.

Unintentionally. A system file has been deleted.

This has led to system instability.

You can go and reply to the system.

Or in a stupid way.

Reinstall the system. Thank you for reading my comments.

A device is used for the chemistry of benzene and liquid bromine.

Device B is to remove the unreacted liquid bromine to obtain pure bromobenzene.

The C device is to remove the volatilized bromine vapor and prevent interference with the hydrogen bromide in the future.

Molecules are constantly doing irregular motion, starting from thermal motion, energy ** from thermal energy, the electron acceleration mentioned on the first floor is just one of the artificial methods of accelerating to the speed of light, so that its large-scale motion can be explained by Newton's kinematics, and the landlord expounds the motion of the electron itself, beyond the scope of Newton's explanation!! And its energy ** thermal energy, also known as thermal motion.

2 electrons will collide with each other, the motion is irregular, the electron cloud of h atom is a good explanation of this, the trajectory of electrons in a certain time is irregular!

3 The maximum number of electrons that can be accommodated in the electron shell is a certain 2 8 8 18 18 32 32 The reason for this is related to the stability of electrons, (1) the principle of Pauli incompatibility.

2) The principle of lowest energy.

3) Hunt's rule explains the reason well, but it does not have to be filled, such as iron in the eighth main group, element 28, and the electron shell is 2 8 8 8 8 2

Electrons move to close to the speed of light and are accelerated by accelerators. Of course, it also depends on the capabilities of the accelerator. The better the accelerator, the closer it is to the speed of light, but it is also more expensive and more difficult.

There is no law in the movement of electrons, and to be explained by quantum mechanics, it can only be inferred by probability that the probability of occurrence is high. The electrons are moving around and colliding.

According to the knowledge of quantum mechanics, when an atom is in the ground state, the arrangement of electrons outside the nucleus follows three principles:

1) Pauli incompatibility principle.

2) The principle of lowest energy.

3) Hunt's rule.

From these three principles, it can be inferred that the number of electrons that can be accommodated in the electron shell is certain.

Issues with data enforcement protection.

My Computer Right-click Properties Advanced Performance Settings Data Execution Protection Add, select your wrong program and add it.

Let me tell you the simplest and most perfect way.

Go to a computer store and buy a quick-install version of the CD.

5 minutes to get the system done again.

The disc system in the computer store is good.

Up to 5 bucks depressed.

What's it like to be here?

The little time you have to ask questions is all about the system.

Your computer is best to restore the system with a one-click restore and backup, first boot the system at the end of the two options, one is to enter the XP system, one is to enter the one-click restore, follow the prompts to do it.

Generally, the reinstallation system of domestic machines is restarted, and after the f10 cursor disappears, press f10 to enter ghost, and then I don't need to say what to do.

If your system has been backed up, open the ghost software and choose to restore, and you can restore the system to its original state.

That phrase means using the module in violation of the address 0048f77c" mtbmucexe " .Reading address 0000002c means that there is an error in the system file.

If it doesn't get better after a while, there are two reasons. Virus.

Another reason is that the optimization software mistakenly deleted some important system files. There is no way to reinstall or restore the start - Programs - Accessories - System Tools - System Restore - select an earlier date to restore and reinstall, then find a good system disk, enter the BIOS settings, first boot as CD-ROM, put in the system CD and select the automatic installation system.

Enter sysc: If it doesn't work, you can only reinstall.

Running msconfig is completely disabled at startup and the ctfom service is closed.

Have you saved the system?

If you don't have spare points, you have to reinstall the system.

Little sister, can't you get into the system? Or do you run some programs after entering the interface and come out of these things?

Take a look at the answer to the computer knowledge learning network Try it.,No, you'll have to reinstall the system.,C disk shouldn't have so many important things.。。。

Workaround :)

Try to run the program in a compatible way. Right-click on the icon - Properties - Compatible - check the box below "Run this program in compatible mode" - you can choose to run it in , or 2000 mode. It is recommended to choose 98 to give it a try.

I'll copy what works for others, and give it to others.

Keep it simple.

If you don't want to delete something, you can repair and install the same system disk, and that's it, and there will be no information in the future.

If you can't find the same system disk, you will have an option not to delete the file if you are installing a system on another disk.

Access Violation, General Protection Fault, or Invalid Page Fault, although not the same thing, is essentially caused by the same error. Access Visualization is often encountered when a program running by a computer user attempts to access a store that is not intended to be used.

access violation at address Hexadecimal Value

in module Application Name

read of address Hexadecimal Value

access violation at address of adress 00000000 means: In address 00000000 access violation, the reading of address 00000000 is prohibited.

Access violation at address 00000000 read of address 00000000.Here's why:

There is no server-side software running, so the client will prompt"access violation at address 00000000, read of address 0000000", open the server program or check the network cable to solve the problem.

In addition, the reason why this problem may occur is because you are running the program in a WinRar window and the program cannot find the main file.

Workaround :)

Try to run the program in a compatible way. Right-click on the icon - Properties - Compatible - check the box below "Run this program in compatible mode" - you can choose to run it in , or 2000 mode. It is recommended to choose 98 to give it a try.

It is recommended to reinstall the system or restore your system backup.

It is recommended that after reinstalling the system, you must make a backup of the clean system, and if you encounter a problem that you can't solve, you can restore the system again, and it will soon be put into use.

Also, don't overuse optimization software, which will cause inexplicable problems in your system until the system goes down.

The new system should be well protected, firewall + antivirus software, although there are many viruses that cannot be deleted and cleaned, but viruses are always ahead of antivirus software, and there is always a solution.

There was an error with the system file. It is possible to be poisoned and make some important files corrupted, just fix it.

First place a 360 security guard and check if there is a Trojan.

There was an error with the system file. Some system modules were deleted by mistake.

It is recommended to reinstall the system or restore your system backup.

There was an error with the system file. If it doesn't get better after a while, there are two reasons. Virus.

Another reason is that the optimization software mistakenly deleted some important system files. There is no choice but to reinstall or restore.

Use the module in violation at address 0048f77c" mtbmucexe " .Read address 0000002c

Is it forbidden for the optical drive to run automatically? Double-click the lower rally to try it out.

If you can't find the drive letter, go to the hardware manager and scan for hardware changes.

Check whether the circuit is connected well, remove the optical drive, check the alcohol for the laser head, and try to change a good disk, but it can't be read, and then consider the optical drive.

Try it on a different disc, it's not a software problem, it's definitely a hardware problem, it's not a disc, it's definitely a CD-ROM drive, nothing else!

Wouldn't it be long after I bought it? As long as you are sure that the dish is good, it is the problem of the machine, and it is still under warranty anyway. If you don't understand it, you won't be there alone.

Isn't it okay to have all the dishes? Most of the time there is a problem with the laser head, you can't read the disc, you can try to disassemble it on another machine. Otherwise, you will directly find after-sales service.

The optical drive turns the light on.,If you don't turn it, it won't turn on.,It's nothing.,You go to my computer and see if you can call the content of the optical drive.。 If you can, that's normal, if you can't, then give Lenovo a **, and they will give a free replacement during the warranty period!

Can I still see the optical drive on my computer? It didn't hang for long

When the computer is just turned on, press the del key to enter the management interface of the motherboard, and then see if there is an optical drive in the IDE interface in the main information, if you can't find it, it's broken.

Lenovo, which has not been bought for a long time, should have a door-to-door warranty.

Also: Don't mess with the things in the motherboard settings.

Brand machines are not allowed to disassemble the chassis casually, and find Lenovo customer service to solve it.

Yes, it's a power supply problem that causes your motherboard to boot up because of the lack of power supply, but your motherboard can't supply enough power to meet your monitor's power.

I also think it's a problem with your plug-in board, so it's better to change it.

There are often customers who burn the power supply of the host because the plug-in board is not good - it doesn't take a few days to burn even a few power supplies, and they won't burn it after replacing the plug-in board.