Introductory Chemistry Flashcards
Define chemistry
the science of the structure and interactions of matter
Define matter
Anything that occupies space and has mass
Define mass
the amount of matter in any living organism or nonliving thing
Define chemical elements
substances that cannot be broken down into simpler form by ordinary chemical means
Currently scientist recognize how many different elements
118
each element is designated by what
chemical symbol
what is the chemical symbol for
- Hydrogen
- Carbon
- Oxygen
- Nitrogen
- Potassium
- Sodium
- Iron
- Calcium
- Hydrogen - H
- Carbon - C
- Oxygen - O
- Nitrogen - N
- Potassium - K
- Sodium - Na
- Iron - Fe
- Calcium - Ca
How many different elements are normally present in the body
26
Just four major elements constitute about how much of the body’s mass
96%
The four major elements found in the body are
Oxygen
Carbon
hydrogen
Nitrogen
Eight Lesser elements constitute about how much of the body’s mass
3.6%
There are 14 elements called trace elements that are present in the human body that together they account for how much of the body’s mass
0.4%
Each element is made up of what
atoms (Smallest unit of matter)
An element consists of who basic parts, what are they
Nucleus and one or more electrons
Example of a trace element is?
Used to make what?
Iodine
Thyroid hormones
a centrally located nucleus contains what
A positively charged protons and an uncharged neutron
Making the nucleus positively charged
what are electrons
tiny negatively charged particles that move about in a large space surrounding the nucleus
The number of protons in the nucleus of atom is called
the Atomic number
the total number of protons plus neutrons in an atoms is referred to as
mass number
electrons move about with a certain region, the region in called
electron shell
If an atom either gives up or gains electrons, it becomes an
Ion
An ion has a equal number or unequal number of protons
unequal
atoms that share an electron are called
???????
a molecule
can be same or different elements
a substance containing atoms of two or more different elements is called
compound
an ion that has an unpaired electron in its outermost shell is called
Free Radical
an example is superoxide
the forces that bind the atoms of molecules and compound together, resisting their separation is called
Chemical bond
the outermost shell of an atom is called a
valence shell
the force if attraction between ions of opposite charges is called
ionic bond
are cation are negative or positive
Positive
are anion are negative or positive
negative
an ionic compound that breaks apart into cations anions when dissolved is called
Electrolyte
when atoms form a molecule by sharing one, two, or three pairs of their otter shells electrons they are called
covalent bond
the greater number of electrons pairs shared does the bond get stronger or weaker
Stronger
in the body ionic bonds are mainly found in
teeth and bones
electrolytes play a roll in
- controlling water movement
- maintain acid base balance
- producing nerve impulses
what is the most common chemical bond in the body
covalent bonds
in some covalent bonds, atoms share the electrons equally, one atom does not attract the shared electron more strongly than the other , this is referred to as
nonpolar covalent bond
in a covalent bond that the sharing of electrons is unequal is called
polar covalent bond
when a hydrogen atom with a partial positive charge attracts the partial negative charge of a neighboring electronegative atom (usually oxygen or nitrogen) it forms what kind of bond
hydrogen bond
what is energy
the capacity to do work
what are the two forms of energy
potential energy
kinetic energy
stored energy is
potential energy
energy in motion is
kinetic energy
chemical energy is a form of
potential energy
where is chemical energy stored
between the bonds of molecules
describe the process of chemical reactions
break of old bonds requires an input of energy and forming new bonds release energy
when two or more atoms, ions, or molecules combine to form new longer molecules the process is called
synthesis reaction
the word synthesis means
to put together
all the synthesis reactions in the body are referred to as
anabolism
when a molecule is split apart it is referred to as
decomposition
AB molecules break down into
A + B
decomposition reactions that occur in the body are collectively referred to as
give an example
catabolism
an example is, the breakdown of large starch molecules into many small glucose molecules during digestion
in general, energy-releasing reactions that occur as nutrients, such a glucose, are broken down via decomposition reactions. Some of the energy released is temporary stored in special molecules called
adenosine triphosphate (ATP)
a reaction that consist of both synthesis and decomposition reaction
exchange reactions
AB + CD = AD + CB
a chemical reaction that can go in either direction under different condition and are indicated by two half arrows pointing in opposite direction
reversible reactions
all the chemical reactions in the body is called
metabolism
chemical in the body can be divided into two main classes of the compounds what are they
inorganic and organic
what are Characteristics of inorganic compounds
lack carbon sometimes
simple
held together by ionic or covalent bond
inorganic acids, bases, and salts dissociate (break apart) into into ions in what solution
water
what are Characteristics of organic compounds
always contains carbon
usually contains hydrogen
always has covalent bond
water makes up what percentage of body mass in lean adults
55 to 60 percent
a acid dissociates (breaks apart) into
hydrogen
a base dissociates (breaks apart) into
hydroxide ions
a salt dissociates into
cation and an anion
neither hydrogen positive or hydroxide negative
examples of organic compounds are
carbohydrates: include sugars, glycogen, and starches and most common source of energy
what are lipids
group of compounds that include triglycerides, phospholipids, steroids, fatty acids, and fat soluble solutions
what are protines
gives structures to the body, regulate enzyme process,, provide protection and help to contract muscles.
what is the principle energy- storing molecule in the body
adenosine triphosphate (ATP)
water is involved in what process
digestion, elimination of waste, circulation, and regulation of body temp
the more hydrogen ions (H+) dissolved in a solution, the more
Acidic
the more hydroxide ions (OH-) the more
basic
the pH scale extends from
0 to 14
what is the midpoint of the pH scale
7
a solution with pH of 7 is
neutral
a change of a whole number on the pH scale represents
a 10-fold change
homeostatic mechanisms maintain the pH of blood between
7.35 and 7.45
how do buffer systems work
prevent rapid , drastic changes in the pH of body fluids by converting strong acids and bases to weak acids and bases.
what is a an example of a buffer system
carbonic acid-bicarbonate buffer system
