In space we feel weightlessness because the earth's gravity has less effect on us. The Earth's gravitational attraction at those altitudes is only about 11% less than it is at the Earth's surface. If you had a ladder that could reach as high as the shuttle's orbit, your weight would be 11% less at the top.
Sound is a type of mechanical wave, which means it requires a material medium for transmission. It results from the vibration of particles.
The speed of sound in mediums varies depending on the property of the medium and a number of other factors which includes; temperature, pressure, and humidity.
Temperature increases the speed of sound wave as particles at higher temperatures tend to possess more energy and thus they will vibrate faster and thus the sound wave will travel faster.
Well formation of metallic bond depends on free electrons.smaal sized atoms hold their electrons more firmly as compared to large size atoms ,this z due to distance of outer shell electrons by nucleus..in this way no of free electrons affect strength of metallic bond..smaal sized atoms release less free electrons..
