Atoms of different elements always combine in the same way.
John Dalton noted that if the components are added to one exacerbated, the share of their masses will dependably be the same. Dalton's been an English scholar. The component mass of that mix is measured by the confirmation of the presence of molecules assembled by John Dalton.
Ionic bonds result when electrons are tranfered between atoms. Covalent bonds result when valence electrons are shared between atoms. You should be able to identify whether an ionic or covalent bond is being formed between atoms.
It shows the evolution of certain species through the bone structures of the fossils.
I believe the answer your looking for is they hang upside down all the time this is one of their survival skills! Hope this helps!