I only need help on the first one. Please help me

No, it is not an example of a mutation.

Explanation:

Mutations occur in the chromosomes of the organism, in this case the fly. A mutation is a permanent alteration in the DNA of the fly. Therefore, if the fly were to have purple wings when it was born then it would be a mutation. However, in this case we dyed the wings of the fly purple. This does not alter or change the DNA in any way to cause a mutation.

Hope this helps!!

- Kay

it's c. elements are placed in rows based on how may valencies electrons have.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.