Zusammenfassung der Ressource
Year 9 science revision
- Heat
- insulators are material that does not allow heat to move through it
- radiant heat
- Transmitted Heat: the temperature of these objects does
not increase quickly when heat reaches them by radiation
- Absorbed heat: their temperature increase quickly when heat
reaches them by radiation
- Reflected heat: the temperature of these objects does not
change quickly when heat reaches them by radiation
- Sound
- Light
- Electricity
- Chemistry
- Endothermic: it describes a process or reaction in which the
systems absorbs energy from it's surroundings in the heat
- Exothermic: describes a process or reaction that releases
energy from the system, usually in the form of heat, but also in a
form of light, electricity or sound
- Acids: are corrosive substances. that means they react with solid
substances 'eating' them away
- Bases: they are indicators that can be used to tell whether a
substance is an acid or a base. when reacted they produce a
color to tell if it's an acid or a base
- Alpha: particles are positively charged. they cannot travel easily through materials
and can be stopped by a sheet of paper or human skin. they pose little hazard to the
external body but can cause serious damage if breathed in
- Beta: are particles that are the same size and mass as electrons, they can have a
negative or positive electric charge and can travel as 99%of the speed of light
- Gamma rays: they're not particles, but bursts of energy released after alpha or beta
particles are emitted and travel the speed of light and are highly penetrating
- the structure of an atom
- neutrons: they have no electric charge and approximately the
same mass as protons.
- Protons have a positive electric charge
- electrons are negative energy particles that orbit the nucleus following paths
commonly referred to as the electron cloud
- Energy basics
- kinetic energy
- moving things have kinetic energy. the heavier a thing is and the faster it moves the more kinetic energy it
has. all moving things have kinetic energy, even large things, like planets, and very small ones, like atoms
- sound energy
- A vibrating drum and a plucked guitar string transfer energy to the air as sound. Kinetic energy from the
moving air molecules transfers the sound energy to your eardrum.
- thermal energy
- Thermal energy is what we call energy that comes from heat. A cup of hot tea has thermal energy in the form
of kinetic energy from its particles. Some of this energy is transferred to the particles in cold milk, which you
pour in to make the tea cooler.
- conduction
- When a substance is heated, its particles gain energy and vibrate more vigorously. The particles bump into
nearby particles and make them vibrate more. This passes the thermal energy through the substance by
conduction, from the hot end to the cold end.
- convection
- The particles in liquids and gases can move from place to place. Convection happens when particles with a
lot of thermal energy in a liquid or gas move, and take the place of particles with less thermal energy. Thermal
energy is transferred from hot places to cold places by convection.
- radition
- All objects transfer thermal energy by infrared radiation. The hotter an object is, the more infrared radiation it
gives off. No particles are involved in radiation, unlike conduction and convection. This means that thermal
energy transfer by radiation can even work in space, but conduction and convection cannot. • Radiation is
how we can feel the heat of the Sun, even though it is millions of kilometres away in space. • Infrared
cameras give images even in the dark, because they are detecting heat, not visible light.
- chemical energy
- Some chemical reactions release energy. For example, when an explosive goes off, chemical energy stored
in it is transferred to the surroundings as thermal energy, sound energy and kinetic energy.
- electrical energy
- A battery transfers stored chemical energy as electrical energy in moving charges in wires. For example,
electrical energy is transferred to the surroundings by the lamp as light energy and thermal energy.
- gravitational potential energy
- A rock on a mountain has stored energy because of its position above the ground and the pull of gravity. This
energy is called gravitational potential energy. This is the energy it would release if it fell. As the rock falls to
the ground, the gravitational potential energy is transferred as kinetic energy.