for the conformation shown, select each hydrogen whose bond to carbon is aligned for effective hyperconjugation with the vacant p orbital on the positively charged carbon. each adjacent carbon will have only one c-h bond so aligned.

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.

the answer is c.the valence of the atoms combine .

pv=nrt

explanation: