Chemical Basis of Life Flashcards
Matter
Anything that has mass and occupies space
3 states of matter
solid, liquid, gas
Atoms
Fundamental building blocks of matter
Periodic Table
Tabular arrangement of chemical elements
Synthetic Elements
All above 92, plus 43 and 61
Four elements make up 96.1% of body mass:
Hydrogen (H), Oxygen (O), Carbon (C), and Nitrogen (N)
9 elements make up 3.9& of body mass:
Calcium (Ca), Phosphorus (P), Potassium (K), Sulfur (S), Sodium (Na), Chlorine (Cl), Magnesium (Mg), Iodine (I), Iron (Fe)
Subatomic Particles
Protons, neutrons, electrons
What is at the nucleus of an atom and what is in its orbit?
Proton & neutron at nucleus, electrons in orbit
Bohr’s Model of Atom
Electrons revolve around the nuclus in energy levels called orbits.
Orbitals
Regions of space around nucleus where electrons are likely to be found. Contained in energy levels.
Atomic Number
Number of protons in nucleus
Atomic mass
Average weight of atom (determined by # of protons & neutrons)
Number of neutrons in an atom
Atomic mass number - atomic number
Noble gases
They have full outermost shell
Octet Rule
Atoms will gain or lose electrons to have a full outer shell of 8e.
Valence
Number of electrons in the outermost shell
Isotopes
Different forms of atoms of the same element. # of neutrons is different
Radioactive Isotopes
Nuclei Unstable. Spontaneously break down into atoms of another element
Compound
Cluster of atoms held together by chemical bonds
Molecule vs Compound
Molecule is formed when two or more atoms join together chemically. Compound is a molecule that contains at least two different elements.
Chemical formulas; subscript meaning?
how many of that kind of atom
Structural formulas
Diagram showing how atoms are arranged
Types of chemical bonds
Ionic bond, covalent bond, hydrogen bond
Intra-molecular vs Inter-molecular bonds
Ionic & Covalent: Intra-molecular
Hydrogen: Inter-molecular
Ionic Bond
Electrons are transferred between atoms to form ions. Electrical attraction of opposite charges forms bond.
Usually outer shell almost empty or full.
Covalent Bond
Electrons are shared between atoms.
Usually outer shell hall-full.
Types of Covalent Bonds
Single bond, double bond, triple bond
Single Covalent Bond
One pair of electrons is shared
Double Covalent bond
Two pairs of electrons are shared
Triple Covalent bond
Three pairs of electrons are shared
Nonpolar Covalent Bonds
Electrons are shared equally
Polar Covalent Bonds
Electrons are not shared equally.
Electronegativity
An atom’s tendency to attract electrons to itself in a chemical bond
The most electronegative element
Fluorine