It may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O). As components of matter, molecules are common in organic substances (and therefore biochemistry) and are what allow for life-giving elements, like liquid water and bre...
So molecules like this ended up on Earth. In fact, what we call meteorites are pieces broken away from comets and asteroids that came in our atmosphere and left their extra-terrestrial organic matter on the surface of primitive Earth.这样的分子最终来到了地球上。事实上，我们所说的陨石是来自彗星...
06.Molecules in the air 32020-04 6 05.Getting in a state 72020-04 7 03.What's an atom? 112020-04 8 02.How have chemist s changed the world? 162020-04 9 01.what's chemistry all about? 342020-04 10 Rocks are chemicals too 502020-05 查看更多 ...
Another way to put it would be to say that air resistance is the result of collisions of the object’s leading surface with air molecules. It can therefore be said that the two most common factors that have a direct effect upon the amount of air resistance are the speed of the object a...
On Earth our daytime sky is bright and blue, That’s because water droplets, dust particles, and molecules in the air are lighted by the sun. 在地球上,白天时候的天空是明亮的蓝色。那是因为空气中的小水滴,粉尘颗粒和小分子使太阳...
Clouds are floating water.There are plenty of water molecules floating eo in the air. When cold water molecules meet dust or salt, they stick together. It makes tiny water droplets.Clouds are made of these tiny water droplets.Where do clouds come from? As the sun warms the Earth, water ...
purification and as an organic synthetic intermediate. It is commonly used in organic synthesis and medicinal chemistry as a tool for drug molecule modification and the synthesis of organic active molecules. It can undergo 1,2-addition reactions with nucleophilic reagents and 1,4-Michael addition ...
Mixturesare formed by just mixing or 'intermingling' (another word which means the same as 'mixing') together two or more substances.Those substances may also be referred to as 'constituents' or 'components' - and may be eitherelementsorcompounds, and be composed of eitheratomsormolecules.There...
high-energy X-rays and ultraviolet (UV) radiation from the Sun. However, because the gas molecules are so dispersed, there isn’t enough density for this heat to be felt in the same way it would be at lower altitudes—essentially, the air is too thin to effectively transfer this energy....
Cellular respiration is the network of metabolic processes that break down molecules ingested from the diet in order to produce ATP, chemical energy for the cell used to power cellular activities and ultimately life. Cellular respiration takes oxygen and food molecules and converts it to ATP ...