Elements are placed in the same column of the periodic table because they share the same number of valance electrons.

True, each column in the periodic table is called a group. The elements in each group have the same number of valence electrons.

When a virus infects a host cell, it uses the cell's machinery to make copies of its own genetic material in a process called replication. finally, during the process of self-assembly, that protein shell and the copies of the virus's genetic material are assembled into new viruses.