Steric Contriubtion to Standard Enthalpies of Activation

[Hirmand_Sarafian_2N]

Can someone explain to me what is the steric contributon to standard enthalpies of activation? Also will this be on the quiz?

[Annie Duong 3L]

We learn that values are often unfavorable, negative values because there is usually a decrease in entropy when reactants go into the transition state. Going into the transition state, there are specific orientation requirements for the reaction and these specifications further contribute to the negative value of . That idea is called the steric contribution.