The Chemistry of Life - Practice Flashcards

25 question-and-answer flashcards covering the core concepts from the notes on the chemistry of life.

What is chemistry?

The study of the composition, properties, and interactions of matter; often called the central science.

What is matter?

Anything that occupies space and has mass, existing as solid, liquid, or gas.

What are the three states of matter and a key characteristic of each?

Solids have definite shape and volume; liquids have definite volume but take the shape of their container; gases have no definite shape or volume.

What is a chemical element?

A pure substance that cannot be broken down into simpler substances by chemical reactions.

Which elements comprise about 96% of the body's mass?

Oxygen, Carbon, Hydrogen, and Nitrogen.

What are trace elements?

Elements present in tiny amounts (~0.4% of body mass) that have important functions; examples include aluminum, boron, chromium, cobalt, copper, fluorine, iodine, manganese, molybdenum, selenium, silicon, tin, vanadium, and zinc.

Who organized the periodic table?

Dmitri Mendeleev, who arranged chemical elements into a chart still used today.

How are elements arranged in the periodic table?

By atomic number and grouped by similar chemical and physical properties.

What is an atom?

The smallest unit of matter that retains the properties of an element.

What are the two main regions of an atom?

The nucleus (containing protons and neutrons) and the electron cloud where electrons orbit the nucleus.

What is a proton?

A positively charged subatomic particle in the nucleus with a mass of about 1 amu.

What is a neutron?

An uncharged subatomic particle in the nucleus with a mass of about 1 amu.

What is an electron?

A negatively charged subatomic particle surrounding the nucleus; mass about 1/1800 amu and contributes to an atom's charge.

What is the atomic number?

The number of protons in the nucleus; equals the number of electrons in a neutral atom.

What is the mass number?

The sum of the protons and neutrons in the nucleus.

What are isotopes?

Atoms of the same element (same protons) that differ in the number of neutrons.

What are radioisotopes?

Isotopes that are unstable and emit energy or particles as they decay; used in medicine and science but can be hazardous with excessive exposure.

What is an ion?

An atom that has gained or lost electrons; cations are positively charged, anions negatively charged.

What is a molecule?

Two or more chemically bonded atoms.

What is a compound?

A substance composed of atoms of two or more different elements.

What is a chemical bond?

An attractive force that holds atoms together, via electron donation, sharing, or transfer.

What is an ionic bond?

A bond formed by electrical attraction between oppositely charged ions (cations and anions), e.g., NaCl.

What is a covalent bond?

A bond formed by sharing electrons between atoms; common in carbon-based molecules and many inorganic molecules like water.

What is the difference between nonpolar and polar covalent bonds?

Nonpolar covalent bonds share electrons equally; polar covalent bonds share electrons unequally, with greater electron density around the more electronegative atom.

What is a hydrogen bond?

A weak attraction between partially charged regions of molecules, important in water and the DNA double helix.