Lecture Exam One (2.1 Atoms, Ions, and Molecules, 2.2 Water and Mixtures)

This is the simplest form of matter to have unique chemical properties

Elements

Each element is identified and arranged within the periodic table by this number

Atomic number

The atomic number of an element is determined by the number of __________ within its nucleus.

Protons

There are _____ naturally occurring elements on earth and ______ of them play normal physiological roles in the human body

91, 24

These six elements account for 98.5% of the human body weight

Oxygen, Carbon, Hydrogen, Calcium, Nitrogen, and Phosphorus

0.8% of the human body weight is determined by these 6 elements

Sulfur, Potassium, Sodium, Chlorine, Magnesium, and Iron

This term refers to the 12 elements which make up only 0.7% of the human body weight

Trace elements

The nucleus of an atom is composed of these particles

Protons and neutrons

These particles are located in clouds around the nucleus of an atom

Electrons

These particles determine the chemical properties of an atom and govern what molecules exist and what chemical reactions can occur

Electrons

This term refers to the regions electrons swarm around the nucleus of an atom

Electron shells

This term refers to the electrons within the outermost electron shell of an atom

Valence electrons

This term refers to the varieties of an element (Each element has at least one of these)

Isotopes

Isotopes differ from one another only in their number of ________ and therefore their __________ mass.

Neutrons, atomic

True or false : All isotopes of a given element behave the same chemically but they differ in physical behavior

True

Unstable isotopes are known as _________ and the process of decay is known as ______________.

Radioisotope, Radioactivity

This term refers to high energy radiation that ejects electrons from other atoms and converts them into charged ions

Ionizing radiation

This term refers to the amount of time required for 50% of an radioisotopes atoms to decay to a more stable isotope

Physical half life

This term refers to the amount of time required for half of a radioisotope to leave the human body

Biological half life

These are the two main methods which drive the biological half life of a radioisotope

Radioactive decay and Excretion

This is the standard unit of radiation dosage

Sievert (Sv)

The standard measurement of radiation (sievert) measures these three characteristics of radiation

Type, Intensity, and Biological effects

These are charged particles with uneven protons and electrons

Ions

These are electrically neutral compounds of anions and cations

Salts

These are substances that ionize in water to form solutions capable of conducting electricity

Electrolytes

These are chemical particles composed of two or more atoms united by a chemical bond

Molecules

These are molecules composed of two or more elements

Compounds

This term refers to molecules with identical molecular formula but different arrangements of their atoms

Isomers

These are the chemical bonds of greatest physiological interest

Ionic, covalent, hydrogen, and van der Waals forces

These bonds are created through the attraction of a cation to an anion

Ionic bonds

These bonds form through the sharing of electrons

Covalent bonds

These bonds are formed when a pair of shared electrons spend an equal amount of time between two nuclei

Non-polar covalent bonds

These bonds are formed when a pair of shared electrons spend significantly more time orbiting on nucleus

Polar covalent bonds

Hydrogen bonds form between a slightly positive hydrogen atom and slightly negative _________ or __________ atom

Nitrogen, oxygen

This is a substance that is physically blended but not chemically combined (each substance retains its chemical properties)

Mixture

These are the main two important aspects of the structure of water

They are joined by polar covalent bonds and the molecule is v-shaped

These are the five properties that allow water to support life

Solvency, adhesion, cohesion, chemical reactivity, and thermal stability

This refers to the ability to dissolve other chemicals

Solvency

Molecules must be __________ to be soluble in water

Polarized / Charged

This refers to the tendency of one substance to cling to another substance

Adhesion

This refers to the tendency of molecules of the same substance to cling to each other

Cohesion

This specific characteristic of water allows it to stabilize the internal temperature of our bodies

Heat capacity

This mixture consists of matter (solute) mixed with a more abundant substance (solvent)

Solution

This is the most common colloid in the human body

Mixtures of protein and water

True or false : Particles within a colloid can pass through most selectively permeable membranes

False (They are too large)

Particles within this mixture are too heavy to remain separated on standing

Suspensions

This is a specific suspension of one liquid in another

Emulsion