Darwin, Evolution, and Chemical Bonds

Vocabulary flashcards covering concepts from Darwin's theory of evolution, chemical bonds, and the essential properties of water.

Darwin

Proposed the working mechanism of evolution.

Natural Selection

The difference in the survival and reproduction of organisms due to environmental forces, resulting in the preservation of favorable traits.

Overproduction

A condition where more individuals are produced than the environment can support, leading to a struggle for existence.

Variations

Completely random differences among members of a population that can be passed on to their offspring.

Fitness

The reproductive success of an individual, where individuals with more favorable characteristics survive and reproduce more.

Increased Proportions

An increase in the number of individuals in a population with a particular favorable trait.

Adaptations

The result of natural selection, where a population becomes better suited to its local environment.

Cation

An element with an overall positive charge (more protons than electrons), formed by losing valence electrons.

Anion

An element with an overall negative charge (more electrons than protons), formed by gaining valence electrons.

Chemical Bonds

Attractive forces between elements.

Ionic Chemical Bond

Attractive forces between ions of different charges, formed from the exchange of electrons.

Covalent Chemical Bond

A bond formed by sharing two or more valence electrons, with its strength depending on the number of shared electrons.

Electronegativity

An atom's affinity for electrons in a covalent bond, which dictates how electrons are distributed.

Polar Covalent Bond

A covalent bond characterized by the unequal sharing of electrons, typically between elements with different electronegativity, resulting in a separation of charges.

Non-Polar Covalent Bond

A covalent bond characterized by the equal sharing of electrons, typically between the same elements or elements with similar electronegativity, resulting in no separation of charges.

Single Covalent Bond

A bond formed by sharing one pair of electrons, e.g., H-H in H₂.

Double Covalent Bond

A bond formed by sharing two pairs of electrons, e.g., H=H.

Triplet Covalent Bond

A bond formed by sharing three pairs of electrons, e.g., H≡H.

Hydrogen Bond

A bond formed from a polar covalent bond between a hydrogen atom in one molecule and a more electronegative atom (like O or N) in another molecule, responsible for many of water's properties.

Cohesion

The property of water molecules sticking to other water molecules due to hydrogen bonding.

Adhesion

The property of water molecules sticking to other surfaces or things due to hydrogen bonding.

High Specific Heat (Water)

A property of water indicating that a large amount of energy is required to change its temperature, meaning it can store a lot of heat.

High Heat of Vaporization (Water)

A property of water where evaporation from a surface causes cooling.

Ice Density

Ice is less dense than liquid water, causing it to float and bodies of water to freeze from the top down.

Good Solvent (Water)

Water's ability to dissolve polar molecules and ions.

Solute

Anything that dissolves in water.

Solution

A combination of a solute and a solvent.

Hydrophobic

Meaning 'water-fearing,' describing molecules that water organizes, often causing them to aggregate.

Hydrophilic

Meaning 'water-loving,' describing molecules that dissolve easily in water.

Ionization (Water)

The process where water breaks apart to form ions, specifically Hydrogen [H+] and Hydroxide [OH-].