Heat & Temperature Flashcards

Flashcards about Heat and Temperature, covering definitions and key concepts.

Energy

Power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines.

Thermal Energy

Energy that provides/gives off heat.

Temperature

Tells you how hot or cold something is and measure how fast the particles in a substance are moving.

Thermometers

More reliable devices that measure temperature.

Galileo

Invented the first air thermometer around 1600, which did not have a precise scale.

Anders Celsius

Developed the 1st precise scale in 1742 and used 'degree' as the unit of temperature.

Calibrate

To mark (an instrument) with a standard scale of readings.

High pressure

Causes ice to melt at temperatures below 0°C.

Low pressure

Water boils before it reaches 100°C.

0°C

The temperature at which ice melts at sea level (Celsius).

100°C

The temperature at which liquid water boils at sea level (Celsius).

Absolute zero

The coldest possible temperature (-273.15 °C).

William Thomson (Lord Kelvin)

Developed the Kelvin scale.

Sensor

A material which is affected by changes in temperature.

Signal

Provides information about the temperature.

Responder

Indicates the temperature with a needle, light, or other digital display.

Lab Thermometer

Used in science class with a range of -20°C to +110°C and accurate to about +/-0.5°C.

Liquid Crystal Thermometer

Often used to measure fish tank temperatures; not very accurate.

Clinical Thermometer

Used to measure human body temperature with a range of 35°C to 42°C and very accurate (+/-0.1°C).

Bimetallic Strip

Made of two different metals joined together, often formed into a coil; when heat is applied, one metal expands faster than the other, and the strip bends.

Thermostat

Uses a bimetallic coil to regulate a device.

Thermocouple

Two wires of different metals are twisted together; when heat is applied to one end, an electric current is produced.

Infrared Thermogram

All objects give off infrared radiation (IR).

Resistance Thermometer

Uses electrical resistance to measure temperature.

Particle Model of Matter

Describes the tiny particles that make up all living things & non-living!

Energy

Gives an object the ability to move, do work, or cause change.

Average Kinetic Energy (Ek)

The average energy of particles.

Thermal energy

The quantity of energy a substance has.

The Law of Conservation

Energy cannot be created or destroyed. It can only be transformed from one type to another, or passed from one object or substance to another.

Expansion

As the average energy (temperature) of particles increases, the spaces between the particles (volume) increases.

Contraction

As the temperature of particles decreases, the volume decreases.

Pure substances

Matter made up of only one kind of substance, which can be a liquid, solid or a gas.

Heat Capacity

Amount of thermal energy that warms or cools the object by one degree.

Specific Heat Capacity

Amount of thermal energy that warms or cools one gram of a material by one degree.

Changes of State

Some substances, like water, can undergo observable changes through all three states of matter à solid, liquid and gas.

Transferring Energy

Energy can be transferred in 3 ways: Radiation, Conduction, and Convection.

Radiation

The transfer of energy in a wave-like form.

Reflection

Occurs if the energy cannot penetrate the surface of the material and bounces away.

Absorbtion

Occurs if the energy penetrates part way into the object.

Transmission

Occurs if the energy passes completely through the object with no absorption of energy.

Conduction

Is the process of transferring heat energy by the direct collisions of the particles (usually in a solid).

Conductors

Transfer heat quickly because they have “free electrons.

Heat insulators

Slow down the rate of heat conduction.

Convection

Is the transfer of energy by the circular motion of the particles and takes place in fluids (liquids and gases).

Energy source

Where the energy comes from.

Transformation

Energy can change its form when it is transferred.

Control Systems

A control device can start and stop the transfer of energy.

Fossil Fuels

Chemicals from plants and other organisms that died and were buried millions of years ago, and today are burned for fuel.

Passive Solar Heating

Uses the materials and design of a house to absorb and store radiant energy in the winter, yet keep the home cool in the summer.

Active Solar Heating

Involve fairly complex mechanical systems and devices called solar collectors.

Photovoltaics

Nonmechanical device that converts sunlight directly into electricity.

Radiant Energy

Energy that is radiated or transmitted in the form of rays, waves, or particles.

Solar Cell

A device that converts radiant energy from the sun into electrical energy.

Fossil Fuel

A fuel formed in the Earth from plant or animal remains.

Non-renewable Resource

A resource that cannot be replaced once used.

Lab Thermometer

Used in science class with a range of -20°C to +110°C and accurate to about +/-0.5°C.

Liquid Crystal Thermometer

Often used to measure fish tank temperatures; not very accurate.

Clinical Thermometer

Used to measure human body temperature with a range of 35°C to 42°C and very accurate (+/-0.1°C).

Made of two different metals joined together, often formed into a coil; when heat is applied, one metal expands faster than the other, and the strip bends.