Chapter 2 - The Chemical Context of Life Flashcards
What is an Element?
Substance that cannot be broken down to other substances by chemical reactions
What is Matter?
Anything that takes up space and has mass
What is a Compound?
Substance consisting of two or more different elements combined in a fixed ratio
What 4 elements account for 96% of living matter?
Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N)
What does the atomic number tell us about an element?
The number of protons and electrons
What is the mass number?
Sum of the protons and neutrons
What is an Isotope?
Different atomic forms of the same element
What is a radioactive isotope?
Nucleus decays spontaneously, giving off particles and energy
What is energy?
Capacity to cause change, for instance, by doing work
What is Potential Energy
The energy that matter possesses because of its location or structure
What is Valence Electrons?
Outermost electrons
What is a Valence Shell?
The outermost electron shell
What is Electronegativity?
The attraction of a particular atom for the electrons of a covalent bond
What is Nonpolar Covalent Bond?
Electrons shared equally (same element)
What is a Polar Covalent Bond?
An atom is bonded to a more electronegative atom, the electrons of the bond are not shared equally
