As he began to teach inorganic chemistry, Mendeleev could not find a textbook that met his needs. Since he had already published a textbook on organic chemistry in 1861 that had been awarded the prestigious Demidov Prize, he set out to write another one. The result was Osnovy khimii (1868–71; The Principles of Chemistry), which became a classic, running through many editions and many translations. When Mendeleev began to compose the chapter on the halogen elements (chlorine and its analogs) at the end of the first volume, he compared the properties of this group of elements to those of the group of alkali metals such as sodium. Within these two groups of dissimilar elements, he discovered similarities in the progression of atomic weights, and he wondered if other groups of elements exhibited similar properties. After studying the alkaline earths, Mendeleev established that the order of atomic weights could be used not only to arrange the elements within each group but also to arrange the groups themselves. Thus, in his effort to make sense of the extensive knowledge that already existed of the chemical and physical properties of the chemical elements and their compounds, Mendeleev discovered the periodic law.
The only thing you need to put the followings into correct order is to remember that the smalles mass - the less volume it has. So, accordnig to this, the order should be like that : An ice crystal- A water molecule-An oxygen atom-The electron cloud-<span>An oxygen nucleus. Hope you will find it helpful!</span>
Well the glaciers can melt and add more water to the oceans/seas and some animals that live in the North Pole will have no where to go...EXAMPLE: polar bears ,penguins, walruses, etc use the glaciers. Polar bears jump onto them to get to land or if they are fighting a walrus they have more fighting ground on land than in the water,etc. (There's a lot more info I just don't know if it's the correct info but what I'm telling you right now is 90% true lol.) also some of the land land can sink like islands or peninsulas(I think)