The correct answer is a descriptive investigation.
An investigation which does not involve hypotheses called descriptive investigation.
Hypotheses are termed as scientific hypotheses and require that one can test it. In hypothesis, previous observation can not satisfactorily be explained with an available scientific theory.
Working hypotheses are being proposed for further research.
Answer:
X = Water (H2O) ; Y = Hydrogen ; Z = Oxygen
Explanation:
2(H2O) -------> 2H2 + O2
My guess on that molecule is nucleus , sorry if it’s not correct
Answer:
From least polar covalent to most polar covalent;
S-I< Br-Cl < N-H< Te-O
From most ionic to least ionic
Cs-F> Sr-Cl> Li- N> Al-O
Explanation:
Electro negativity refers to the ability of an atom in a bond to attract the shared electrons of the bond towards itself.
Electro negativity difference between two atoms is a key player in the nature of bond that exists between any two atoms. A large difference in electron negativity leads to an ionic bond while an intermediate difference in electro negativity leads to a polar covalent bond.
Based on electro negativity differences, the bonds in the answer have been arranged in order of increasing polar covalent nature or decreasing ionic nature.