To determine the formula formed between elements P and Q based on their valence electrons, we need to consider how they would likely combine to achieve a stable electron configuration.
Element P has 6 valence electrons, and element Q has 1 valence electron. Both elements will strive to achieve a stable electron configuration, usually by gaining, losing, or sharing electrons.
Since element P has 6 valence electrons, it will tend to gain 2 electrons to achieve a stable octet (8 electrons in the valence shell). This would result in a net charge of -2 on the P ion.
On the other hand, element Q has 1 valence electron and would be more likely to lose that electron to achieve a stable configuration with an empty valence shell. This would result in a net charge of +1 on the Q ion.
Considering the charges, element P with a charge of -2 and element Q with a charge of +1, the formula formed between them would involve a transfer of electrons to form an ionic compound. The ratio of ions in the compound can be determined by finding the least common multiple (LCM) of the charges.
The LCM of 2 and 1 is 2. Therefore, it takes two Q ions (+1 charge each) to balance the charge of one P ion (-2 charge). Hence, the formula formed between element P and element Q would be P2Q.