Eight science reviews, eight science homework

Summary. Hello, I am a teacher in this area, I am inquiring for you here, please wait for a while, don't go away, my side will reply to you right away <>

<> eight scientific assignments.

Hello, I am a teacher in this area, I am inquiring about you here, Wu Lian, please wait for a while, don't go away, I will reply to you immediately <>

<>Hello, Kai Yin, I'm glad to answer your question about the <> of the digging grandson

The homework of the eight lower subjects is shown in the figure below, I hope the above content will be helpful to you, I wish you a happy study, <>

Isn't it a question that doesn't work, and it's the first question S3 shouldn't be a low-temperature file after closing the celebration tour? The series connection should be that the greater the resistance, the more heat is discharged, and the more disturbances are generated, why is the topic a medium temperature file?

Hello! pro (3).

1～6：abcabacdd

7: PO2 ignites P2O5.

When the temperature reaches the ignition point and comes into contact with air (or oxygen), the lighter does not ignite after it has not burned.

White phosphorus combustion is not carried out in a sealed device, and the phosphorus pentoxide produced pollutes the air :ba

10: Beaker.

The gas in the gas collector cylinder is reduced, and the pressure is reduced, which causes the water in the beaker to enter the gas collector cylinder 21 and the nitrogen gas reacts with other substances in the cylinder and decreases.

3. Combustion does not necessarily require oxygen (or nitrogen) to support combustion under certain conditions.

There are two resistors, R1 = 4 ohms, R2 = 8 ohms, connected in series on the volt voltage, the current passing through R1 is ( ) ampere, and the voltage at the end of R2 is ( volts. If they are connected in parallel and connected to volts, the current in R1 is ( amps, and the voltages at both ends of R2 are ( ) volts.

2. The picture on the right is the circuit connected by a classmate. After closing the electric bond, he noticed that one light was not on. Please analyze the light that does not turn on in the circuit (l2), and help the state to modify the circuit according to different requirements.

1) If you want to make L1 and L2 become a series circuit, you should (go to close and touch off the wire BC) 2), if you want to make L1 and L2 become a parallel circuit, you should (remove the CF and connect FA).

L2 If Ming Li wants to make L1 and L2 a series circuit, it should be ( remove the wire BC If L1 and L2 are to be connected in parallel, they should ( remove CF and connect FA).

The gas P2O5 after the combustion of red phosphorus is a toxic gas that is delayed by hand, so that the gas will not be emitted in the air and endanger the human body.

Energy savings (no ignition, fuel savings).

The advantages are: simple operation and small error.

On the one hand, it saves energy, and on the other hand, it prevents air from entering the bottle when inserting a small spoon with red phosphorus, which can affect the experimental results.