Chapter 2.1: The chemical foundations of life

Match the evolutionary force (left) with the correct definition (right).

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periodic table

A chart of the elements showing the repeating pattern of their properties

Reactant

A chemical substance that is present at the start of a chemical reaction

reversible reaction

A reaction that can go in either direction, reactants turn into products, when products go beyond the threshold, some product reverts back into reactants.

Chemical bonds

Atoms form bonds with other atoms, they obtain electrons needed for a stable electron configuration.

What is the octet rule?

Atoms tend to gain, lose or share electrons in order to have a full set of valance electrons; with the exception of the innermost shell, the atoms are most stable when they have 8 electrons.

ionic bond

Forms between ions with opposite charges

Molecules

Groups of two or more atoms held together by chemical bonds

Noble gasses are

Highly stable as single atoms, they are resistant to share electrons from their filled outer shells, they are considered nonreactive.

Ions and Ionic Bonds

Ions have a deficit or surplus of electrons resulting in a net + or - charge. Ionic bonds are important in protein structure.

Radioisotopes

Isotopes that have unstable nuclei and undergo radioactive decay. It describes the energy loss, of a nucleus searching for stability.

Electryolytes

Substances that release ions in water; these ions are necessary for nerve impulse conduction, muscle contraction and water balance.

Atomic mass

The average mass of all the naturally occurring isotopes of an element

Products

The elements or compounds produced by a chemical reaction.

Mass number

The number of protons and neutrons that determine the element mass

Chemical reactions

This occurs when two or more atoms bond together to form molecules or when bonded atoms break apart.

Equilibrium

a steady-state of relative reactant and product concentration in reversible chemical reactions in a closed system

Isotopes are

atoms of the same element with different atomic masses. Some elements have naturally occurring isotopes.

law of mass action

chemical law stating that the rate of a reaction is proportional to the concentration of the reacting substances

balanced chemical equation

has the same number of atoms of each element on both sides of the equation

Anions

negatively charged ions Designated by its elemental name and the ending changes by adding -ide.

irreversible reaction

not able to change back to a former state; impossible to revert back

valence shell

outermost electron shell

Cations

positively charged ions

Orbitals

regions around the surrounding nucleus that contain electrons.

Chemical reactivity

the ability to combine and to chemically bond with each other

electron configuration

the arrangement of electrons in an atom's electron shell.

Electron transfer

the movement of electrons from one element to another

atomic number

the number of protons in the nucleus of an atom

Electron orbitals

volumes of space surrounding the atomic nucleus where electrons are likely to be found.