social capital. Stock of community's goodwill and trust acquired by an organization over the years, through its understanding and addressing of the concerns and priorities of the citizens. See also social value.
All electromagnetic radiation travels at the same speed (in a vacuum). Electromagnetic radiation travels very quickly. There is nothing which can travel faster. The speed is 300,000,000 m/s in a vacuum (that is 300 million metres per second-not easy to imagine!). Electromagnetic radiation can be thought of as particles or waves (the word radiation is also used for radioactivity).
Sound can travel through anything made of molecules-even water! There is no sound in space because there are no molecules there to transmit the sound waves. Electromagnetic waves are different from sound waves because they do not need molecules to travel. This means that electromagnetic waves can travel through air and solid materials-but they can also travel through empty space. This is why astronauts on spacewalks use radios to communicate.