Apositively charged glass rod attracts object x. the net charge of object x

The charge on the object X is negative.
Because we know that opposite charges attract each , be it positive r negative.
But same charges repel each other. i.e. a positive will always repel a positive charge and a negative will always repel a negative charge see figure for more clarification

Molybdeum(mo)orruthenium (ru)actually, elements with similar chemical properties as technetium would bemn, re, and bh. this is because elements in the same group/family (column) have similar chemical properties. elements in the same period (row) have the same number of energy levels (or shells).