Chapter 2: The Chemical Context Of Life Flashcards
What are trace elements?
Elements that are required by organisms in minute qualities.
What are essential elements?
Elements that are necessary for living organisms.
Neutrons and protons are measured in…
Daltons.
What is the atomic number of an element and where is it located?
The unique number of protons of an element. Located to the bottom left of the elements symbol.
What usually is the charge of an atom?
Neutral
What is mass number, where is it located, and what is it measured in?
The sum of protons and neutrons. Located at the top left of an elements symbol. Daltons.
Isotopes have more (blank) than other atoms of the same element.
Neutrons.
ALL isotopes behave (blank) in chemical reactions.
Identically.
What is atomic mass?
The average of the atomic masses of all the elements naturally occurring isotopes.
What is the power of radioactive decay?
Changing the number of protons and transforming atoms to that of a different element.
What part of the atom is involved in chemical reactions?
Electrons.
What is matter’s natural tendency?
To move to the lowest state of potential energy.
Where is the potential energy of an electron the highest?
The more distant it is from the nucleus.
What determines an electrons potential energy?
It’s energy level, or electron shell which increases in energy the further away it is from the nucleus.
What determines the chemical behavior of an atom?
It’s valence electrons.
What are the two strongest chemical bonds?
Covalent and ionic bonds.
What is an elements valence?
The number of covalent bonds it can form.
What is electronegativity?
The attraction of a particular atom for the electrons of another atom.
What is a nonpolar covalent bond?
When two atoms have the same electronegativity.
What is a polar covalent bond?
When one atom is bonded to a more electronegative atom. Unequal attraction.
What is a hydrogen bond?
The noncovalent attraction between a hydrogen and an electronegative atom.
What is evaporative cooling?
As a liquid evaporates the surface of the liquid that remains cools down.
Why is water a good solvent?
Bc of it’s polarity.
What is a hydration shell?
The sphere of water molecules around each dissolved ion.
What is a buffer?
A substance that minimizes changes in the concentrations of H+ and OH- in a solution.
What is ocean acidification?
When CO2 dissolves in sea water forming carbonic acid and lowering the pH of water.
