In the f-block of the periodic table, actinides have partially filled forbitals in the principal energy level, while lanthanides have partially filled forbitals in the
principal energy level.
fourth

i'm not sure

explanation:

i'll try whatever you got

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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