Answer:
the empirical formula of the metal fluoride.
Explanation:
Mass of copper heated = 8.249 g
Mass of copper fluoride formed = 13.18 g
Mass of fluorine gas in copper fluoride = x

Moles of copper :

Moles of fluorine:

For the empirical formula divide the smallest mole of an element with all the moles of elements present in the compound.

The empirical formula of the copper fluoride = 
the empirical formula of the metal fluoride.
The complete question is
Comparison of a homeodomain protein from yeast and Drosophila shows that only 17 of its 60 amino acids are identical. How is it possible for a protein to change over 70% of its amino acids and still fold in the same way?
Answer:
Many different strings of the amino acid can give rise to the identical protein folds. The amino acid differences between the Drosophila and homeodomain proteins from yeast are the functional proteins which do not change their structure and function.
There is a several amount of folding required which can cause change in the protein structure.
There is a basic functional proteins common in both the organism which do not change its structure and function.
Answer:
Most metals have <u>luster</u> which means they <u>reflect</u> light
Explanation:
When light, which is made up of energetic photons, comes in contact with the surface of a metal, it is absorbed due to the corresponding energy gaps present between the metal orbital. The absorbed photons results in the raising of the energy levels of electrons within an atom of the metal which later drop back to a lower energy level and re-emit the photons which can now be observed as the metallic luster.