Which periodic trend does not agree with observed trends on the periodic table? the ionization energies of Group 2 elements are less than that of Group 3 elements as the atomic numbers of the halogens increase, the electronegativities decrease atomic radii increase from top to bottom down a group of elements O ionization energies generally decrease from left to right across a period of elements​

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i  

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).

56 moles of   lieter in chemistry

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.

that's it!

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