Lecture 3 - Chemistry Flashcards
What is matter?
The stuff of the universe, has mass, occupies space
What is energy?
Energy affects matter
Kinetic energy puts matter in motion
Potential energy is stored energy
What is the law conservation of energy?
Energy created cannot be destroyed
The law conservation of energy Is how energy can be converted from one form to another
What are elements?
Substances that can’t be broken down into simpler substances
What are isomers?
Same molecular formula but different structures
What are atoms?
Smallest units of matter that retain the properties and characteristics of an element
Explain the atom structure
Proton: Positive charged particles in the nucleus
Neutrons: Neutral charge particles in the nucleus 
Electrons: Negatively charged particles in shells around the nucleus (determine chemical property)
What is Dalton?
A standard unit for measuring the mass of atoms and their subatomic particles
What are isotopes?
Same atomic number but different atomic mass
Different from normal in the number of neutrons
What are radioisotopes?
Isotopes that lose subatomic particles overtime
What does it mean by “ Half life of isotope”?
Time required for half the radioactive atoms in an isotope to decay into more stable form
What is an ion?
A charged atom
ANION: Gains one or more electrons and has a negative charge
CATION: Loses one or more electrons and has a positive charge
Molecules vs. Compounds
Molecules: Made by binding two or more atoms
Compounds: Made from two or more different atoms
Valence shells
Shell 1 holds only 2 electrons
Shell 2 hold Max 8 electrons
Shell 3 holds 8 or more electrons
Atom with full valence shell is chemically stable
Because this requires 8 electrons it’s called the octet rule
What is an ionic bond?
The transfer of valence shell electrons from one atom to another, resulting in ions
