Given an element with seven valence electrons, how many chemical bonds will usually form?

Answer : The element is belongs to the group 17 having the seven valence electrons and they will usually form one chemical bonds to another element.

Explanation :

As per given in the question that the element has seven valence electrons that means the seven electrons are present in their outermost energy level or shell.

Form the given information we conclude that, the group number is, 17 (because there are 7 valence electrons in outermost shell).

The elements belongs to group 17 are fluorine, chlorine, bromine and iodine and they are the halogens.

The general electronic configuration of halogens are, that means they have seven valence electrons in their outermost shell and they need only one electrons to complete their octet. So, they will usually form one chemical bonds by accepting one electrons from the other elements.

Hence, the element is belongs to the group 17 having the seven valence electrons and they will usually form one chemical bonds to another element.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.