The statement that correctly summarizes the trend in electron affinity is the second option: it tends to be more negative across a period".<span> Electron affinity is the energy absorbed or released by a neutral atom when it absorbs an electron. The more negative the electron affinity the higher the affinity of the atom for an additional electron. So as the electronegativity trends to increase across a period, indicating that the atoms of the left side pull stronger the electrons, the fact that the electron affinity is more negative across a period tells that the atoms to the left accept better an additional electron.</span>
Electrons in sigma <span>bonds remain localized between two atoms. Sigma </span><span>bond results from the formation of </span><span>a molecular orbital </span><span>by the end to </span><span>end overlap of atomic </span>orbitals. Electrons<span> in pi</span> bonds can become delocalized between more than two atoms. Pi bonds result from the formation of molecular orbital by side to side overlap of atomic orbitals.
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It is advisable to wear long sleeve when when a student is working in a chemistry lab so that to protect arms from lab chemicals. when someone enter the chemistry lab to wort or to study should be well prepared with appropriate gears and security measure to avoid injury.
<span>When an ice cube is placed on a kitchen counter, heat will flow from the ice cube to the counter, causing the molecules in the counter to move more slowly. The molecules of the counter move more slowly because the heat transferred to them from the ice has reduced their kinetic energy.</span>
