D.
Electromagnetic waves are received and then vibrate a speaker which produces sound waves.
Explanation:
The telephone has a receiver-transducer component that can receive electromagnetic wave - radio waves spectrum- and transform them into electric energy. This electric energy is then transformed into sound energy by a speaker. This is how we're able to listen to a phone call.
The opposite happens when we speak on the phone. The sound energy is transformed into electric energy by a microphone – the reverse of a speaker. The transducer now changes the electric energy into electromagnetic waves that travel through space to the recipient in the phone conversation.
Answer:
The correct answer would be A.
Answer:
1. Density can be used to identify a substance
2. Density can be used to ascertain whether a substance will float in water.
Explanation:
The calculation of the density of a substance can be used to identify the substance. If the density of a substance is calculated accurately, and compared with a table of standard densities, then we can identify that substance.
Also, density determines whether an object will float or sink in water. If an object is less dense than water then it will float in water. If it is denser than water, then it will sink in water.
Answer:
Electrostatic Van de Waals forces act between molecules to form weak bonds. The types of Van der Waals forces, strongest to weakest, are dipole-dipole forces, dipole-induced dipole forces and the London dispersion forces. The hydrogen bond is based on a type of dipole-dipole force that is especially powerful. These forces help determine the physical characteristics of materials.
<span>H2C2O4(aq) + 2OH- --> C2O4^2- + 2H2O(l)</span>
