1. The degree of heat and cold of an object is called temperature.

2. To judge and measure the temperature accurately, we must choose a scientific measuring tool-thermometer, which is made according to the law of liquid expanding when heated and contracting when cooled.

3. The use of thermometer: First, look at its range (the temperature range of the highest and lowest temperature that can be measured), and then look at its scale value (the value represented by a small cell).

4. Precautions for using the thermometer: ○ 1. All the glass bubbles of the thermometer are squeezed into the measured liquid. Don't touch the bottom or wall of the container. 2. Please wait a moment after the glass bulb of the thermometer invades the liquid to be measured. 3. When reading, keep the glass bulb of the thermometer in the liquid. The line of sight should be flush with the upper surface of the liquid column in the thermometer.

Two. Melting and solidification

1. The process of changing a substance from solid to liquid is called melting.

The process that a substance changes from a liquid to a solid is called solidification.

3. Solid state melting (endothermic) liquid state

Solid solidification (exothermic) liquid state

4. Crystal: Some solids absorb as much heat as possible during melting, but the temperature remains the same. For example, waves, ice and various metals all have a certain melting temperature.

5. Amorphous: Some solids are melting. As long as they keep absorbing heat, the temperature will keep rising. There is no fixed melting temperature, such as wax, rosin, glass and asphalt.

6. The temperature at which a crystal melts is called the melting point. Amorphous crystals have no definite melting point.

7. There is also a definite temperature when it freezes. This temperature is called freezing point. The freezing point and melting point of the same substance are the same. Amorphous crystals have no definite freezing point.

8. Melting absorbs heat. Solidification releases heat.

Three. Vaporization and liquefaction

1. The change from liquid to gas is called vaporization.

The change from gas to liquid is called liquefaction.

3. Boiling is a violent vaporization phenomenon that occurs simultaneously inside and on the surface of liquid (water boiling is a violent vaporization phenomenon).

All kinds of liquids have a definite temperature when they boil. This temperature is called boiling point.

Vaporization that can occur at any temperature is called evaporation.

6. Evaporation and boiling are two ways of vaporization.

Four. Sublimation and Sublimation

1. The direct change from solid to gas is called sublimation.

2. The direct transformation of matter from gas to solid is called sublimation.

3. sublimation requires heat absorption. Condensation requires heat release.

I. Fees

1. Friction objects attract light and small objects, which is the phenomenon of friction electrification.

There are only two kinds of charges in nature. The charge on a glass rod rubbed with silk is called positive charge, and the charge on a rubber rod rubbed with wool is called negative charge.

3. Like charges repel each other. Different charges attract each other.

4. The quantity of charge is called the quantity of charge. Referred to as charging. The unit of charge is coulomb. It is called the library for short. Symbol C.

5. The charge can move directionally in the metal bar. Metals are conductive. Some objects are good at conducting electricity. They are called conductors. Metal, human body, salt solution and so on are all conductors. Some objects don't conduct electricity. They are called insulators. Rubber, glass and plastic are insulators.

Two. Current and circuit

1. Circuit composition: ○ 1. Power supply: dry battery, storage battery and generator.

○2. Electrical appliances: devices that work with electricity.

○3. Switch: Control the on-off of the circuit.

○4. Conductor: connecting circuit

2. The direction of positive charge movement is defined as the direction of current.

Three. Series and parallel connection

1. series circuit: a circuit that connects electrical appliances one after another. There is only one path after the current flows out from the positive pole of the power supply. After passing through each electrical appliance, it directly flows back to the negative pole of the power supply and cuts off any circuit. The whole circuit is off, and the switch can be connected in series at any position of the circuit without affecting the control of the circuit.

2. Parallel circuit: a circuit that connects electrical appliances in parallel. The connection point between electrical appliances is called the branch point of parallel circuit. The circuit part from the two-stage power supply to the branch point is called the trunk line. Each circuit between two branch points is called a branch. Cut off a branch. Other branches are still working. So the switch in the trunk can control the on-off of the whole circuit. The branch switch can only control the on-off of its branch.

4. The intensity of water flow

1. Current is a physical quantity indicating current intensity. Usually represented by the letter I, the unit is ampere. The symbol is a. (

2. Precautions for using ammeter: ○ 1. The ammeter is connected in series in the circuit under test. Current flows in from the positive electrode. 3. Estimate. Try to touch. Select the appropriate range.

Verb (abbreviation for verb) household circuit

1. Household circuit components: ○ 1. Incoming line: live line. Zero line 2. Watt-hour meter: measures the electric energy consumed by users in a certain period of time. 3. Master switch (knife switch): controls the on-off of indoor and outdoor. 4. Fuse: When the current in the circuit is too large, the fuse will melt. Automatic cut-off circuit (its protection function)

2. One of the two transmission lines entering the house has been grounded outdoors. One is called zero line, and the other is called terminal line, commonly known as fire line.

I. Voltage

1. To generate a current in the circuit, there must be a voltage across it. The function of power supply is to provide voltage across the electrical appliance.

2. The voltage is usually represented by the letter U, and the voltage is used on both sides. The unit of voltage is volts. The symbol is v. The voltage of the home lighting circuit is 200V V.

3. Use of voltmeter: When measuring the voltage across an element with a DC voltmeter, it should be connected in parallel with this element. One end marked with [-] should be close to the negative pole of power supply, and the other end should be close to the positive pole of power supply. The maximum measured value of the range used must be greater than the voltage across the circuit to be tested.

Two. resist

1. Resistance indicates the resistance of the conductor to current. The greater the resistance of the conductor, the greater the resistance of the calibration conductor to the current. Different conductors usually have different resistances. Resistance is a characteristic of the conductor itself.

2. The resistance of a conductor is usually represented by the letter R, and the unit of resistance is ohm.

3. The resistance of the conductor is related to the material, length (the longer the conductor, the greater the resistance) and cross-sectional area (the smaller the cross-sectional area of the conductor, the greater the resistance).

It is worse than metal. It is better than nonmetal. It is usually called a semiconductor.

Three. Ohm's Law

Ohm's Law: The current in a conductor is directly proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor.

(formula: I=U/R, where: U- voltage-volt (v), R- resistance-ohm (), I- current-ampere (a).

2. The total resistance of the series resistor is greater than that of any sub-resistor.

3. The total resistance of parallel resistors is less than that of any branch resistor.

4. Open circuit and short circuit: ○ 1. The circuit is not connected. This fault is an open circuit. 2. The phenomenon that the bright spots that should not be connected in the circuit are directly connected together is called short circuit.

Four. electric energy

1. The unit of electric energy is kilowatt hours. The symbol is kilowatt hours. The more commonly used unit of energy is joule. This symbol is abbreviated as J.

Verb (abbreviation for verb) electricity

1. Electric power represents the speed of consuming electric energy. The electric power is expressed by p and the unit is watt. The symbol is W (P=W/t, where: W- consumed electric energy-joule, t- time-second, P- electric power-watt).

2. 1 kWh is the electric energy consumed by electrical appliances with power of 1kW.

3. The normal working voltage of electrical appliances is called rated voltage. The power of electrical appliances under rated voltage is called rated power.

4.P=UI(I- current ampere, U- voltage volt, P- power watt)

1. Colorful material world

1. mass is the basic property of an object. The unit of mass is kilogram. The symbol is kg.

2. The mass per unit volume of a substance is called its density. The formula p = m/v.

Two. Motion and force

1. The change of object position is called mechanical motion. The motion and rest of an object are relative.

2. The unit of speed is meters per second, and the symbol is meters per second (v=s/t 1m/s=3.6km/h).

The uniform motion of an object along a straight line is called uniform linear motion, which is the simplest mechanical motion.

4. Force is the action of objects on objects. Force can stop moving objects, move stationary objects, change the speed and direction of objects and deform them.

The unit of force is Newton. Cattle for short. The symbol is n.

5. Size, direction and action point will affect the action effect.

6. The forces between objects are interactive.

7. Newton's first law: all objects are always in a state of static or uniform linear motion without force.

8. The property that an object keeps a constant state of motion is called inertia. Newton's first law is also called the law of inertia.

9. Balance of two forces: two forces acting on the same object. If the magnitude is equal and the direction is opposite, the two forces will balance each other on the same straight line.

Three. Lihe machinery

1. Elasticity: An object deforms when stressed and returns to its original state when it is not stressed. This property of an object is called elasticity.

The force exerted on an object due to the gravity of the earth is called gravity. All objects on the earth are affected by gravity.

The direction of gravity is always vertical downward.

The gravity of an object is directly proportional to its mass. The ratio of gravity to mass is about 9.8N/kg.

(g = mg) g = 9.8 N/kg

The point of gravity is called the center of gravity.

6. Friction: Two objects in contact with each other. When they move relative to each other, a force will be generated on the contact surface to hinder the relative movement. This force is called friction.

7. The metabolism of friction is related to the pressure acting on the surface of an object. The greater the surface pressure, the greater the friction, and the magnitude of friction is also related to the roughness of the contact surface. The rougher the contact surface, the greater the friction.

8. Lever: It can rotate around a fixed point under the action of force. This hard stick is a lever.

9. fulcrum: the point around which the lever rotates, force: the force that makes the lever rotate, resistance: the force that hinders the lever from rotating, arm of force: the distance from the fulcrum to the line of force action, and arm of resistance: the distance from the fulcrum to the line of resistance action.

10. Power× power arm = resistance× resistance arm

1 1. The power arm is longer than the resistance arm and is called the labor-saving lever. Power arm is shorter than resistance arm, which is called labor-saving lever.

12. The function of the moving pulley: labor-saving and effortless. It can change the direction of an object.

13. The function of the moving pulley: it can save labor, but it cannot change the direction of the object.

Four. Pressure and buoyancy

1. The pressure per unit area of an object is called pressure (P=F/S).

At the same depth, liquid has pressure in all directions. The pressure in all directions is equal and the depth increases. The greater the pressure drop of liquid, the pressure of liquid is also related to the density of liquid. At the same depth, the greater the density of the liquid, the greater the pressure.

3. Liquid pressure formula: P=pgh

4. Communicator: When the liquid in the communicator does not flow, the liquid level in each container is always the same.

In gas and liquid, the greater the speed, the smaller the pressure.

6. The buoyancy of an object immersed in a liquid is equal to the gravity of the liquid it displaces. This is the famous Archimedes principle. Formula: F float =G row.

Verb (abbreviation for verb) work and mechanical energy

1. The product of the force and the distance moved in the direction of the force is called work. Formula: W=Fs.

Using any machine will not save work. This conclusion is called the working principle.

3. The ratio of useful work to total work is called mechanical efficiency.

The work done in unit time is called P=W/t, and the formula is p = w/t.

5. Kinetic energy and potential energy are collectively called mechanical energy.

Math and English. I'll call you when I have time.