rè yǔwēndù
·热与温 度(Heat and temperture)
rè duì wùzhì de yǐngxiǎng
·热对 物质 的 影 响(Effects of heat on matter)
wēndù wùzhìshòurè hòuwēndù shàngshēng wùzhìsanrè hòuwēndù xiàjiàng
[1]温 度：（A）物质 受热后 温度 上升。 物质 散热后 温度下降。(When matter is heated temperature rises, when cooled temperature drops)
cè liangwēndù cèliangyí qì wēndùjì biāozhǔndānwèi shèshìdù
[2]测量 温度：（A）测量仪器：温度计(thermometer) （B）标准单位：摄氏度（’C）(Standard unit for temperature is degree Celcius)
rè duìwùzhìde yǐngxiǎng
[3]热对物质的 影响(Effects of heat on matter)：
wùzhìshòurè péngzhàngwùzhì yùlěngshōusuō
（A）物质受热 膨胀。物质遇冷 收缩。(When matter is heated, it expands; when cooled, it contracts)
rèzhànglěngsuō yuánlǐ zàishēnghuózhōngde yingyòng
（B）热胀冷缩 原理在生 活中 的应用：
"受热膨胀，遇冷收缩"
huǒchētiěguǐzhī jiānliú yǒudekōngxì
·火车铁轨之间 留有 的空隙(gaps in railway tracks)
diànxiàngānshàngsōngchí de diànxiàn
·电线 杆上 松弛的 电线(more sagging during hot day)
wēndùjì lǐ yètǐ de shēngyǔjiàng 温度计 里液体的 升与降(Liquid in a thermometer rises and falls)
We depend on electricity in our daily lives. Electricity has made our lives easier and more comfortable. There are many sources of electricity. Many appliances in our homes and schools use electricity. However. we must be very careful when using electrical appliances. Why?
Some electrical appliances use dry cells to make them work. Dry cells produce electricity. There are also other sources of electricity such as accumulator, dynamo and solar cell. They are examples of batteries.
Accumulators are used in vehicles such as motorcycles, cars and lorries. Dynamos generate electricity. They are used to light up the bulb of bicycle. Satellites get their electricity from solar cells. Solar cells transform light energy into electricity. We can also get electricity from hydroelectric power stations.
An electrical circuit is made up of a power source, wires and other components such as a bulb and a switch. The dry cell is a source of electrical energy for the circuit. A switch is used to break or complete a circuit. The wire allows electricity to flow through the circuit. The bulb lights up because electricity flows through it.
Electricity is useful in our everyday life. Electrical appliances need proper handling because they can cause injury if they are not used properly. Mishandling of electrical appliances can cause. There are safety precautions that must be taken when using electrical appliances.
Do not touch switches with wet hands.
Do not connect too many electrical appliances to one power point.
第五课。能(Energy) 。无所不在的能 (Energy is everywhere) 。能的转换(Energy transformation--energy can be transformed from one form to another) 。可更新和不可更新的能源(Renewable and Non-renewable Energy sources)
néngdexíngshì tàiyángnéng rè néng huàxuénéng diànnéng dòngnéng shēngnéng shìnéng guāngnéng hézǐ néng
2]能的形式(Different forms of energy)：太阳能(solar energy)。热能(heat)。化 学 能(chemical)。电 能(electrical)。动能(kinetic)。声能(sound)。势 能(potential energy)。光 能(light)。核子能(nuclear energy)。
wǒménbùkě yǐ chuàngzàohuòxiāomiènéng dànshìkě yǐ bǎnéngcóngyī zhongxíngshìzhuanhuànchénglìngyī zhong xíngshì
3] 我们不可以创造或消灭 能， 但 是可以把能 从 一种 形式转换成 另 一种形式。(Energy cannot be created or destroyed; it can only be changed from one form to another.)
[.] Energy in our daily life:
Each day we experience multiple forms of energy. For example, in the morning you eat breakfast (chemical energy), walk/ bike/ drive to school (mechanical energy / kinetic), and come into a classroom full of light (light energy) and sound (sound energy).
On the board are magnets (magnetic energy) holding items in place, shooting a rubber band across the room is an elastic (elastic energy to kinetic energy); A pencil falling to the ground is (gravitational energy transforms to kinetic energy), at the front of the room is a smartboard with the day's lesson (electrical energy to light energy). Even though we may just be learning the names, we are very used to using all forms of energy.
[.] Energy conversion/transformation:
[.] Forms of Energy:
[.] Energy:
Energy is important to our lives. We use energy to do work. Energy lights up our cities. Energy moves our cars, trains and enables us to watch televisions. What would happen if there is no energy? Living things carry out life processess. Energy is needed to carry out these processes. Energy is also needed by non-living things. The energy is used to make them usable. The Sun gives us heat and light energy. Plants use sunlight to make food. Humans and animals get energy form the food they eat. Their sources of food include plants and other animals.
Fuels such as coal, petroleum and natural gas are sources of energy too. These fuels are formed from dead plants and animals that lived millions of years ago.
Energy is found in different forms. The batteries in a toy car produce electrical energy to move it. Objects that move have kinetic energy. A burning candle gives off light energy and heat energy. A strectched rubber band in a catapult has potential energuy.
Energy can be transformed form one form to another. Switching on the light transforms electrical energy into light energy. A burning candle transforms chemical energy into light energy and heat energy. Solar powered signal light uses sunlight as the source of energy. The solar energy is transformed into electrical energy and then into light energy.
The energy we use everyday comes from various resources. These resources are divided into renewable energy and non-renewable energy.
第4 课：植物的生命过程 ·植物的自卫（Plants and self-defense) ·植物如何确保物种的生存(How do plants ensure survival of its species?) ·植物物种生存的重要性(The importance of survival of plant species )
diànxiàngānshàngsōngchí de diànxiàn
串联电路(series circuit)：灯泡相继地连接，电流只有一条通路。如果一个灯泡坏了，电流不能流通，所以令一个灯泡也不会亮起来！
刺
细毛。
