Basic Chemistry Flashcards
Matter
Anything that takes up space and has mass, to include solids, liquids, and gases in our surroundings and body
Energy
The capacity to dowry or put matter into motion; may be converted from one form to other; some energy always unusable
Potential energy
Stored energy or energy of position
Kinetic energy
Active or working energy
What are the forms of energy involved in body functioning?
Chemical, electrical, radiant, and mechanical; chemical (bond) is the most important
Elements
Unique substances that cannot be decomposed into simpler substances by ordinary chemical methods
Which 4 elements make up 96% of the body weight?
Carbon, hydrogen, oxygen, and nitrogen
What are the building blocks of elements?
Atoms
What do atoms consist of?
Positively charged protons, negatively charged electrons, and uncharged neutrons
What is located in the atomic nucleus?
Protons and neutrons, which make up the atom’s total mass
Where are the electrons located?
Outside the nucleus in the electron shells; the number of electrons equals the number of protons.
What are the identifying elements of an atom?
The atomic number (p+) and the mass number (p+ + n0)
What is an isotope?
Different atomic forms of the same element, which vary only in the number of neutrons that contain; the heavier species tend to be radioactive
What is a radioisotope?
The more heavy and unstable of the isotopes; decompose to more stable forms by emitting alpha or beta particles or gamma rays; useful in medical diagnosis and treatment and in biomedical research
What is a molecule?
The smallest unit resulting from the chemical bonding of two or more atoms; if the atoms are different, they form a molecule of a compound
What is a compound?
A substance composed of two or more different elements, the atoms of which are chemically united
What is a mixture?
Physical combination of solutes in a solvent; mixtures components retain their individual properties and can be physically separated; may be homogeneous or heterogeneous
What are the types of mixtures?
In order of decreasing solute size, solutions, colloids, an d suspensions
How are solution concentrations typically designated?
In terms of percent or molarity
What is an electron shell?
Also known as an energy level, it is the area of space within an atom that electrons occupy
What is the valence shell?
The shell farthest from the nucleus
Which electrons are the most energetic?
The ones in the valence shell
What is a chemical bond?
An energy relationship between valence shell electrons of the reacting atoms; atoms with an incomplete valence shell interact with other atoms to achieve stability
What is a chemically unreactive, or inert, atom?
An atom with a full valence shell or eight valence shell electrons
What is an ionic bond?
A chemical bond formed when valence shell electrons are COMPLETELY transferred from one atom to another; also called an “electrovalent bond”
What is a covalent bond?
A chemical bond formed when atoms SHARE electron pairs
What is a non polar molecule?
When electron pairs are shared equally in a covalent bond
What is a polar molecule, or dipole?
When electrons pairs are unequally shared in a covalent bond.
What is a chemical reaction?
A reaction involves the formation, breaking, or rearrangement of chemical bonds
What are the types of chemical reactions?
Either anabolic (destructive) or anabolic (constructive) reactions; include synthesis, decomposition, and exchange reactions
What is an oxidation-reduction reaction?
May be considered a special type of exchange (or decomposition) reaction
What is an exergonic reaction?
A chemical reaction where energy is liberated
What is an endergonic?
A chemical reaction where energy absorbed
Explain energy flow in chemical reactions.
bonds are energy relationships and there is a net loss or gain of energy in every chemical reaction
Explain the reversibility of chemical reactions
If reaction conditions remain unchanged, all chemical reactions eventually reach a state of chemical equilibrium in which the reaction proceeds in both directions at the same rate
Are all chemical reactions reversible?
Yes, but many biological reactions go in only one direction because of energy requirements or the removal of reaction products
What factors influence the rate of chemical reactions?
When particles collide and valence shell electrons interact; the smaller the reacting particles, the great their kinetic energy and the faster the reaction rate; higher temperature or reactant concentration, as well as the presence of catalysts
What is the atomic number?
the number of protons in the atoms of a particular element (Hydrogen atoms contain one proton and therefore has the atomic no. 1
what is the atomic weight of an atom?
approximately equals the number of protons and neutrons in its nucleus
what are ions?
atoms that gain or lose electrons, hence becoming electrically charged
What is a decomposition reaction?
when the bonds within a reactant molecule break so that simpler molecules, atoms, or ions form
AB –> A + B
What is a synthesis reaction?
when two or more atoms (reactants) bond to form a more complex structure (product)
A + B –> AB
What is an exchange reaction?
parts of two different types of molecules trade positions; AB + CD –> AD + CB
What is an example of an exchange reaction?
When an acid reacts with a base, producing water and a salt
What is the definition of a reversible reaction?
When the product(s) of the reaction can change back to the reactant(s) that originally underwent the reaction
What is a catalyst?
particular atoms or molecules that can change the rate (not the direction) of a reaction without being consumed in the process
What are electrolytes?
substances that release electrically charged ions in water
This type of electrolyte releases hydrogen ions in the water
acid
This type of electrolyte releases ions that bond with hydrogen ions
base; NaOH –> Na+ + OH-
How is pH measured?
Measured by the concentration of hydrogen ions (and hydroxide ions) in a substance
Water is an important _____ because many substances readily dissolve in it.
solvent
What is a substance that dissolves in water and is broken down into smaller and smaller pieces, eventually to molecular-sized particles, called?
solute
how do inorganic and organic molecules differ?
Organic molecules contain carbon AND hydrogen
name the inorganic substances common in body fluids
water, oxygen, carbon dioxide and salts
how do electrolytes and non electrolytes differ?
Electrolytes release electrically charge ions in water
