CHAPTER 2.1 Flashcards
science of the structure and interactions of matter. All living and nonliving things consist of matter, which is anything that occupies space and has mass
chemistry
the amount of matter in any object, which does not change.
mass
the force of gravity acting on matter, does change
weight
one or two letters of the element’s name in English, Latin, or another language.
chemical symbol
oxygen, carbon, hydrogen, nitrogen
major elements
calcium, phosphorus (P), potassium (K), sulfur (S), sodium, chlorine (Cl), magnesium (Mg), and iron (Fe)
lesser elements
used to generate ATP, a molecule used by cells to temporarily store chemical energy.
oxygen
backbone chains and rings of all organic molecules: carbohydrates, lipids (fats), proteins, and nucleic acids (DNA and RNA).
carbon
ionized form (H+) makes body fluids more acidic.
hydrogen
Component of all proteins and nucleic acids.
Nitrogen
hardness of bones and teeth; ionized form (Ca2+) needed for blood clotting, release of some hormones, contraction of muscle, and many other processes.
Calcium
Component of nucleic acids and ATP; required for normal bone and tooth structure
phosphorus
Ionized form (K+) is the most plentiful cation (
potassium
Component of some vitamins and many proteins
Sulfur
most plentiful cation, essential for maintaining water balance
Sodium
Ionized form (Cl−) is the most plentiful anion
chlorine
needed for action of many enzymes
magnesium
Ionized forms (Fe2+ and Fe3+) are part of hemoglobin and some enzyme
iron
compose individual a toms
subatomic particles
dense central core of an atom
nucleus
regions around the nucleus
electron shells
The first electron shell (nearest the nucleus) never holds more than _ electrons
2 Electrons
e second shell holds a maximum of _ electrons, and the third can hold up to __ electrons.
8 and 18 electrons
number of protons
atomic number
