BIO: Chapter 2 Vocbulary Terms

Matter

Any substance that occupies space and has mass.

Elements

Unuiqe forms of matter with specific chemical and patinas properties that cannot break down into smaller substances by ordinary chemical reactions.

Atom

The smallest unit of matter that retains all of the elements’ chemical properties.

Nucleus

contains protons and neutrons

Proton

The positively charged region of an atom

Neutron

The uncharged charged region of an atom

Electrons

The negatively charged region of a atom

Atomic Number

The number of protons in an element

Atomic Weight

The calculated mean of the automic weights of its naturally occurring isotopes.

Isotopes

Different forms of an element that have the same number of protons but a different number of neutrons.

Radioisotopes

Isotopes that emit neutrons protons, and electrons, and attain more stable atomic configuration.

Periodic Table

Organizes and displays different elements.

Chemical Reactivity

The ability to combine and to chemically bond with eaachother.

Molecules

Two or more atoms chemically bonded together.

Octet Rule

Atoms are more stable energetically when they have eight electrons in their valence shell

Valence Shell

The outermost electron shell

Chemical Rections

When two or more toms bond together to form molecules or when bonded atoms break apart.

Balanced Chemical Equation

When end element’s number of atoms is the same on each side of the equation.

Compounds

Contain Atoms of more than one type of element.

Irriversable

The equations that Ibrahim and unidirectional arrow.

Reversible Reactions

Those that can go either direction.

Cations

positive ions that form by losing electrons

Electron Transfer

When electrons move from one element to another

Ionic Bonds

Form between ions with opposite charges

Electrolytes

Why certain salts are referd by physiologists

Polar Covalent Bond

When atoms unequally share the electrons as the electrons are attracted more to one nucleus than the other.

Nonpolar Covalent Bonds

Form between two atoms of the same element or between different elements that share electrons equally.

Hydrogen Bond

Common type of bond and regularly occurs between water molecules.

Van Der Waals Interactions

Weak attractions or interactions between moleules.

Hydrophilic

When something is loving water

Hydrophobic

Fear of water

Heat Vaporizeation

The amount of energy required to change one gram of a liquid substance to a gas.

Evaporation

Water’s individual molecules acquire enough energy from other water molecules such that some surface water molecules can escape and vaporize.

Solevent

A substance capable of dissolving other polar molecules and ionic compounds.

Sphere of Hydration

Molecules will form hydrogen bonds with water, surrounding the particle with water molecules.

Dissosiation

Occurs when atoms or groups of atoms break off from molecules and from ions.

Cohesion

Water molecules are attracted to eachother, keeping molecules together at the liquid gas.

Surface tension

The capacity of a substance to withstand rapturing when placed under tenssion of stress.

Adhesion

The attraction betweeen water molecules and other molecules.

Acid

A substance that increases hydrogen ions’ correlation in a solution, usually by having one of its hydrogen atoms dissociate.

Made

Provides either hydrocortisone ins or other negatively charged bonds that combine with hydrogen ions.

PH Scale

An inverse logarithim

Bufferssss

Keeps the body PH carefully maintained in the narrow range required for survival.

Hydrocarbons

organic Molecules consisting entirely of carbon and hydrogen

Aliphatic Hydrocrbons

Consists off linear chains of cyclopentane and cyclohexane

Aromatic Hydrocarbons

Consists of closed ring of carbon atoms with altering singe and double bonds.

Isomers

Molecules that share the same chemical formula but differ in the placement (structure) of their ions and/or chemical bonds.

Structual Isomers

Differ in the placement of their covaleent bonds.

Geometric isomers

Alternatively have similar placements of their covalent bonds.

Enantiomers

Moleccules that share the same chemical structure and chemical bonds but differing the three dimensional placement of atoms so that they are non-superimposable mirror images.

Functional Groups

Groups of atoms that occur with molecules nd other specific chemical properties to those molecules.

Substituted hydrocarbons

Molecules with other elements in their carbon backbone.