Unit 1.1 Chemistry of Life Practice Flashcards

A set of vocabulary flashcards covering the basics of atomic structure, chemical bonding, and life-essential elements based on the Unit 1.1 Chemistry of Life lecture.

Matter

The substance that makes up everything; it is composed of atoms.

Atom

The basic unit of matter, composed of protons, neutrons, and electrons.

Protons

Positively charged subatomic particles with a mass of $1$ located in the nucleus.

Neutrons

Subatomic particles with a neutral charge ($0$) and a mass of $1$ located in the nucleus.

Electrons

Negatively charged subatomic particles with a mass of approximately $0$ that orbit the nucleus.

Elements

Different kinds of atoms; approximately $25$ chemical elements are essential for life.

Atomic number

The number of protons in an atom, which identifies the element and corresponds to the number of electrons in a neutral atom.

Essential Elements (96%)

The four elements that make up $96\%$ of living matter: carbon ($C$), hydrogen ($H$), oxygen ($O$), and nitrogen ($N$).

Remaining Elements (4%)

The four main elements that make up most of the remaining $4\%$ of living matter: phosphorus ($P$), calcium ($Ca$), sulfur ($S$), and potassium ($K$).

Trace elements

Elements required in quantities less than $0.01\%$, such as boron ($B$), iron ($Fe$), and zinc ($Zn$).

Isotopes

Atoms of an element with a different number of neutrons, making them heavier; some are unstable and undergo radioactive decay.

Octet rule

The tendency of atoms to drive chemical reactions by completing or emptying a partially filled outer (valence) electron shell.

Ionic bonds

A weak bond formed by the transfer of an electron ($e^-$), resulting in the formation of positive and negative ions.

Cation

A positively charged ion formed during the transfer of electrons in an ionic bond.

Anion

A negatively charged ion formed during the transfer of electrons in an ionic bond.

Covalent bonds

A strong chemical bond formed when atoms share a pair of electrons ($e^-$) to form molecules.

Double covalent bonds

A very strong bond formed when two atoms share two pairs of electrons ($e^-$).

Carbon Bonding

In life, this element always forms $4$ bonds, allowing it to form large molecules.

Polar covalent bonds

A type of bond where the pair of electrons ($e^-$) is not shared equally between atoms due to differences in electronegativity.

Electronegativity

The strength of attraction an atom has for shared electrons; for example, oxygen has a higher value than hydrogen in a water molecule.

Hydrogen bond

An attraction between the positive hydrogen ($H$) atom in one water molecule and the negative oxygen ($O$) atom in another molecule.

Van der Waals forces

Very weak interactions between nonpolar substances caused by random variations in the electron distribution of a molecule.