Chapter 2: The Chemistry of Life Flashcards
What is comprised of matter?
Any substance in the universe that has mass and occupies space
What does matter exist as?
Solid, Liquid, or Gas
What is matter made up of?
Atoms
What happens when you get enough of the same atom together?
You have an element
What is at the core of all atoms?
A nucleus
How many subatomic particles are nucleus’ comprised of?
2
Protons and Neutrons
What are protons?
Positively charged and 1 mass unit
What are Neutrons?
No associated charge and 1 mass unit
What orbits the nucleus?
Electrons, which are negatively charged and almost zero mass
What is the Atomic Mass?
The number of protons + Number of neutrons
What is the Atomic Number?
Number of protons, which determines the element
What do electrons determine?
They determine the chemical behavior of atoms, as they are associated with energy
What energy of position does electrons have?
Potential energy
What do electrons occupy?
Energy levels, which are also known as electron shells, of an atom, which are complex, 3-D volumes of space called orbitals
What is the purpose of orbitals?
Orbitals are where electrons are most likely to be found
Atoms tend to be more reactive when they have
a) complete electron orbitals
b) incomplete electron orbitals
b) incomplete electron orbitals
What will atoms do in order to completely fill their outermost electron shell?
Atoms will lose, gain, or share electrons
These actions are the basis of chemical bonding
What happens when electrons move to a lower energy level, closer to the nucleus?
Energy is released
What happens when electrons move further away from the nucleus?
Energy is required - intake of energy
What are ions?
Atoms that have gained or lost one or more electrons
What are isotopes?
Atoms that have the same number of protons but DIFFERENT numbers of neutrons
What occurs when isotopes are unstable?
They break up into particles with lower atomic numbers (protons)
Known as radioactive decay
What are some uses of radioactive isotopes?
Dating fossils
Medical procedures
Sterilizing food