CHAPTER TWO Chemical Level of Organization Flashcards
what is chemistry?
study of the structure of matter
what is matter?
anything that takes up space and has mass
what is mass?
the amount of material in matter
solid?
fixed volume and fixed shape in ordinary temperatures and pressures. Solids possess particles that are held tightly together and are typically the densest of the three states.
liquid?
maintain a constant volume but have no fixed shape. Instead, their shape is determined by the shape of its container. The particles of liquids are loosely held together and are typically less dense than solids. Examples: water, soda, alcohol.
gases?
do not maintain a constant volume or fixed shape. Gases can be compressed or expanded; unlike liquids they will fill a container of any size. The particles of a gas independent of each other and therefore result in the least dense state. Example: air in our atmosphere.
Matter is composed of one or more types of substances called __?
elements
how many natural occuring elements?
92
approximately 96% of human body weight is created by only what four of them: _____
Oxygen (65%), Carbon (18.6%), Hydrogen (9.7%), and Nitrogen (3.2%).
11 principle elements that are most abundant in the human body?
CHON Oxygen, carbon, hydrogen, and nitrogen are among the 11 principle elements that are most abundant in the human body. Others include: calcium, phosphorus, potassium, iron, sodium, chlorine, etc.
The human body also contains 14 other elements in very small amounts which are?
These are known as the trace elements such as copper, zinc, manganese, and fluorine.
what is atom?
are the smallest indivisible unit of an element and are therefore the smallest stable units of matter
what to know about atoms?
- Everything around us is composed of atoms in varying combinations.
- Atoms are composed of subatomic particles,
what are the subatomic particles?
protons,nuetrons, and electrons
nucleus?
The nucleus contains one or more protons and it may contain neutrons as well.
how is atom’s mass determined?
The mass of the atom is primarily determined by the number of protons and neutrons in the nucleus.
what is electron cloud?
electrons of the atoms whirl rapidly around the nucleus
what is electron shell?
Electrons are often shown in a fixed orbit around the nucleus
element?
a pure substance consisting only of one type of atom
chemical symbol?
an abbreviation; Most of the symbols reflect the English names of the element but others reflect their names in other languages
atomic number?
of an atom defines the number of protons in the atom. Hydrogen (H) is the simplest atom, with an atomic number of 1. Thus an atom of hydrogen contains one proton
neutral atoms?
possess the same number of protons and electrons. A neutral atom of Hydrogen possesses one proton and one electron.
ion?
atoms possessing a charge
cation?
electron donor; positively charged atoms created by the loss of one or more electrons Na+
anion?
electron acceptor; negatively charged atoms created by the gaining of one or more electrons Cl-
mass number?
total number of protons and neutrons
All atoms of the same element possess a constant number of ___.
protons
isotopes?
atoms whose nuclei contain the same number of protons(same identically chemical properties), but different numbers of neutrons.
atomic mass?
The actual mass of an atom is known as its atomic weight, expressed as dalton. the atomic weight of an element is an average mass number that reflects the proportion of different isotopes; mass of protons (fixed) +mass of nuetrons (varies)
chemical bonds?
are INTERACTIONS that STABILIZE the outer energy levels of atoms.
reactive?
outer shell not full
inert?
outer shell is full
ionic bonds?
chemical bonds created by the TRANSFER of electrons from one atom to another atom
ionic bonds create what kind of charges?
transfer of electrons creates two ionized atoms: one a cation and the other an anion.
Ionic bonds are common in the formation of inorganic compounds such as ___.
acids, bases, and salts.
covalent bonds?
chemical bonds that form between neutral atoms rather than ionized atoms; Covalent bonds SHARE their electrons with each atom.
Covalent bonds are usually associated with ___?
organic compounds such as starch, proteins, lipids, etc.
single covalent bonds exist when__pair of electrons are shared
one
double covalent bonds exist when __ pair of electrons are shared between __ atoms.
two,two
polar covalent bonds?
UNEQUAL sharing of electrons due to the electronegativity of the atoms
nonpolar covalent bonds?
are those where the atoms share the electrons EQUALLY An example would be an oil or fat.
molecules?
made up of two or more atoms chemically joined together
compounds?
are chemical substances made up of atoms from two or more different elements, regardless of the type of bonds joining them together
Cells remain alive and functional by ____chemical reactions
controlling
These changes occur as atoms in the reacting substances, called ____, are rearranged to form different substances, called ___.
reactants, products
metabolism?
All of the reactions under way in the cells and tissues of the body at a given moment b. All of the reactions under way in the cells and tissues of the body at a given moment constitutes its metabolism.
work?
is the movement of an object or change in the physical structure of matter
Energy?
is the capacity to perform work.
Energy has no ___and does not ___ ___ ___. It can only be measured by its effects on ___.
mass, does not take up space, matter
potential energy?
stored energy
kinetic energy?
energy of movement
chemical notation rules?
a. The symbol of an element indicates one atom of that element.
b. A number preceding the symbol of an element indicates more than one atom of that element.
c. A subscript following the symbol of an element indicates a molecule with that number of atoms of that element.
d. Substances to the left of the arrow indicate the reactants in the chemical reaction while substances to the right of the arrow indicate the products from the reaction. The arrow indicates the direction of the reaction and reads as “yields”.
e. A superscript + or – sign following the symbol of an element indicates an ion.
decompostion reaction
(also called a catabolism) the chemical bonds of large molecules are broken down into less complex, smaller molecules.
a. Hydrolysis is a common decomposition reaction used to break down organic compounds.
b. ABC yields A + B + C or BOOKWORM = BOOK + WORM
sysnthesis reactions?
(also called an anabolism) smaller particles are bonded together to form larger, more complex molecules.
a.Dehydration synthesis is a common example of a reaction used to build complex organic molecules.
b. A + B + C yields ABC, or NOTE + BOOK = NOTEBOOK
exchange reactions?
parts of the reacting molecules are shuffled to produce new products that are neither smaller nor less complex.
a. AB + CD yields AC + BD or NOTEBOOK + WORM = NOTE + BOOKWORM
4. Chemical reactions can be reversible. A + B yields AB, then AB yields A + B.
5 factors effecting chemical reactions?
- Properties of the reactants
- Temperature
- pH
- Concentration and pressure
- Enzymes lower the activation energy requirements for chemical reactions.
Enzymes ___ the activation energy requirements for chemical reactions
lower
exergonic?
chemical reactions that release more energy that is required to run the reaction are said to be