Ahypothesis is a statement that can be tested through a scientific investigation. what is the purpose of writing a hypothesis?

The purpose of a hypothesis is to find the answer to a question.

Explanation:

A hypothesis is a statement which is written as a source of prediction which is based upon the assumption of the cause of a natural event or process. The purpose of the hypothesis is basically to find the relevant answers to the scientific question. It is based upon few evidences and the entire statement of the hypothesis is tested using experimental procedures.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).