SCIENCE FINALS GR 7

• MAP is a two-dimensional graphical representation of an area, land or sea, depicting physical features.
• GLOBE is a three-dimensional spherical model of the earth.
• LONGITUDES is a vertical imaginary lines that run from north to south of a map or globe.
• LATITUDES is a horizontal imaginary lines that run from east to west of a map or a globe.
• Equator is an imaginary line drawn around the earth equally distant from both poles.
• TROPICS - Countries located in this zone experience a tropical climate where the annual average temperature is above 18 degrees Celsius.
• NORTHERN TEMPERATE ZONE - 23.5"N Countries located in these zones experience four seasons
• SOUTHERN TEMPERATE ZONE - Only experiences 2 seasons
• POLAR/FRIGID ZONES - Countries located in these zones experience cold temperatures all year round.
• GEOGRAPHIC COORDINATE SYSTEM - system that is used to locate places using the degrees of latitude and longitude.
• NATURAL RESOURCES - materials created and gathered from nature that humans use to survive and satisfy their needs.
• RENEWABLE NATURAL RESOURCES - resources that can grow again or can be replaced after lit is consumed.
• NONRENEWABLE NATURAL RESOURCES - are resources that cannot be replaced once consumed.
• A wave is a disturbance that carries energy through matter or space.
• ~A medium is the matter through which a wave travels.
• VIBRATION - a repeated motion and produced by a back-and- forth or up-and-down movement of an object.
• Electromagnetic wave - Capable of transmitting its energy through a vacuum (empty space) Produced by the vibration of charged particles. All light waves are examples of electromagnetic waves.
• Mechanical wave-Not capable of transmitting its energy through a vacuum. - Require a medium in order to transport their energy. - A sound wave is an example of a mechanical wave.
• MECHANICAL WAVE - It requires a medium to propagate.
• ELECTROMAGNETIC WAVE - It does not require a medium to propagate.
• Transverse wave - particles of the medium move in a direction perpendicular to the direction that the wave moves
• Longitudinal wave - particles of the medium move in a direction parallel to the direction that the wave moves
• Surface wave - particles of the medium undergo a circular motion

  neither longitudinal nor transverse
• Crest - the highest point of a wave
• Trough - the lowest point of a wave
• Amplitude- the height of a wave
• Wavelength- the distance between adjacent crest or troughs
• Frequency- the number of waves passing a given point
• Pitch -The highness or lowness of sound
• High pitch sound = high frequency sound wave

  Low pitch sound = low frequency sound wave
• High frequency wave = lot vibrations per second Low frequency wave = few vibrations per second 
• Vibrational frequencies beyond 20,000 Hz are called ultrasonic frequencies while extremely low frequencies below 20 Hz are known as infrasonic frequencies.
• Loudness - Determined by the amplitude of the sound wave
• Decibel (dB) is used to measure sound intensity or loudness
• Threshold of hearing -Sound level of the quietest sound that can be heard -Around o dB
• Threshold of pain -Sound level which can cause pain and damage to the ears Around 120 dB
• Timbre - a.k.a tone color or tone quality - Used to distinguish between two different sounds that have the same pitch and loudness - Helps identify what produced the sound
• Pure tone -the simplest waveform have a soft, pleasant tone quality
• Complex tone - consists of two or more simple tones
• SOUND WAVES - are longitudinal waves created from a vibrating source - it requires a medium.