A hygrometer is an instrument for measuring the humidity of the air or a gas .
Wavelength is also measured in metres (m) - it is a length after all. The frequency, f, of a wave is the number of waves passing a point in a certain time. We normally use a time of one second, so this gives frequency the unit hertz (Hz), since one hertz is equal to one wave per second.
<span>Isotopes are atoms of a particular element that contain a different number of neutrons.
An atom or element have same number of protons and electrons, but when there is a change in number of neutrons, this is called isotope of that element. There are many elements that have their isotopes like carbon have three isotopes Carbon 12, 13 and 14.</span>
Photosynthesis requires energy, making it an endothermic reaction. Light, generally sunlight, is the source of this energy. The process converts the sun’s electromagnetic energy into chemical energy, which is then stored in chemical bonds in the plant. Sunlight is the primary source of energy on the surface of Earth.
<span>solution of KI becomes saturated at 10 degrees when around 135-138g KI are added to 100 g of water, so it should be still unsaturated, A. unsaturated (although it is very close to saturation)</span>
