Why are the elements in groups 3 to 12 known as tranition elements

According to periodic trend, which of the following most likely has the highest ionization energy? kr be ni sc

What rule is used to determine how many covalent bonds an element can form? a. the number of covalent bonds is equal to six c the number of covalent bonds is equal to five minus the group number plus the group number b. the number of covalent bonds is equal to eight d. none of the above minus the group number select the best answer from the choices provided

Which factor is likely to impact the possible number of compounds ?