Unit 1: Fundamentals of Chemistry Flashcards
The four elements that make up 96%+ of living cells
hydrogen, oxygen, carbon and nitrogen
The atomic number is
the number of protons in an atom’s nucleus
Covalent bond
sharing of an electron pair between two atoms. symbol: single line
Ionic bond
electrostatic attraction between oppositely charged ions
Hydrogen bond
a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other
Polar covalent bond
atoms share electrons unequally
Nonpolar covalent bond
atoms share electrons equally
The first (innermost) electron shell has a capacity of
2 electrons
The second electron shell has a capacity of
8 electrons
The third electron shell has a capacity of
8 electrons
Atoms with a full outer electron shell will __ form chemical bonds with other atoms
not
Electro-negativity
the tendency of an atom to attract electrons
Matter
Any substance that occupies space and has mass
Elements
matter that cannot break down into smaller substances and are made up of one type of atom.
Atom
the smallest unit of matter that retains all of the element’s chemical properties
The atoms center contains (2)
protons and neutrons
The atom’s outermost region holds
its electrons in orbit around the nucleus
Atoms contain (3)
protons, electrons, and neutrons
The valence shell
The outermost shell in a Bohr model
When two or more atoms chemically bond with each other, the resultant chemical structure is a
molecule or compound.
Cations
are positive ions that form by losing electrons
Anions
Negative ions form by gaining electrons. End in “ide”
Molecule
One or more types of atoms bonded together
Ion
an atom or group of atoms with an electric charge
Atomic number
Number of protons
A neutral state is when
There is the same amount of protons and electrons
Any line end or bend is a
Carbon
Why must pH be kept within a certain range in a cell or body compartment?
enzymes only work within a certain range of pH
What properties of water are due to its hydrogen bonds?
high heat vaporization
high specific heat capacity
ice is less dense than liquid
it’s cohesion
it’s ability to dissolve many other compounds
The structure of DNA comes from
PBS (phosphate, base and sugar)
Nucleic acids are made from what monomers
Nucleotides
