Ch 2: Atomic Structure and Chemical Bonding Flashcards
What is matter?
anything that takes up space and has mass
What is an element?
substance that cannot be broken down to other substances by chemical reactions
What is a compound?
substance consisting of two or more different elements combined in a fixed ration
What is the organization of matter?
matter–> compound–> element–> atoms–> subatomic particles
What is a trace element?
a chemical element that is present inonly minute quantities
What is an atom?
smallest unit of matter that still retains the properties of an element
Proton
positive charge
Electrons
negative charge
Neutrons
neutral
What is an atomic nucleus?
the center of an atom with protons and neutrons
What keeps electrons orbiting the nucleus?
the attraction between opposite charges keeps electrons orbiting the nucleus
What is an atomic number?
the number of protons within the element
The atomic number tells us what?
it tells us the number of protons and the number of electrons in an electrically neutral atom
What is a mass number?
total number of protons and neutrons in the nucleus of an atom
Mass number equals
protons + neutrons
Atomic number equals
protons and electrons
Number of neurons equals
mass number-atomic number
What is atomic mass?
total mass of an atom
What is an isotope?
atoms of same element with different number of neutrons and therefore different mass
What is a radioactive isotope?
the nucleus decays, giving off particles and energy
What is a half-life?
the time is takes for 50% of the parent isotope to decay
What is radiometric dating?
process where scientists measure the ratio of different isotopes and calculae how many half-lives have passed since an organsim was fossilized or a rock was formed
What is energy?
the capacity to cause change
What is potential energy?
the energy that matter possesses because of its location or structure
