The Intermediate Disturbance Hypothesis Suggests Species Richness

Low rates of disturbance, competitively dominant species would outcompete all other species (K selected) At high levels of disturbance, species would be continually driven extinct and only good colonists and well disperse (r-selected) would persist. Intermediate disturbance, species richness is greatest in areas where disturbances are neither too large nor too small but are of intermediate size.

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#Unit 1. Molecules and their Interaction Relevant to Biology

The greater the effective nuclear charge the more tightly an electron is held in by the nucleus because there is less electron shield between the valence electrons and the nucleus, and so, the smaller the radius.

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#Unit 1. Molecules and their Interaction Relevant to Biology

Ranks the following in increasing atomic radius

S, Mg, Al

S: 16-10 +6

Mg: 12-10 = +2

Al: 13-10 +3

So: S < AlMg

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#Unit 1. Molecules and their Interaction Relevant to Biology

Electron affinity: The enthalpy change that results from adding an electron to a gaseous atom.

Electron affinity is becoming less negative (less exothermic) and less likely to gain an electron. 

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#Unit 1. Molecules and their Interaction Relevant to Biology

Electron affinity: The enthalpy change that results from adding an electron to a gaseous atom.

Electron affinity is becoming less negative (less exothermic) and less likely to gain an electron. 

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#Unit 1. Molecules and their Interaction Relevant to Biology

#Id: 7755

#Unit 1. Molecules and their Interaction Relevant to Biology

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used.