CHEM Vocab EXAM 1 Flashcards
A ___ is made up of only one component, and its composition does not vary.
pure substance
A ____ is a substance composed of two or more components in proportions that can vary from one sample to another.
mixture
___ can not be chemically broken down or decomposed into simpler substances.
Elements
___ are composed of two or more elements chemically combined in a fixed definite ratio.
Compounds
Basic submicroscopic particles that constitute the fundamental building blocks of ordinary matter.
Atoms
Substances formed when two or more atoms come together (bond) in specific geometric arrangements.
Molecules
Two or more metals in a homogenous mix.
Alloy
A set of tested hypotheses forms the basis for a ___ , but it is testable, fallible, subject to
modification after more observation.
theory
A possible explanation for an observation.
hypothesis
Summarizes what happens.
Law
___ are brief summaries of experimental data.
Laws
“Matter is neither created nor destroyed” is the definition of which law?
Law of conservation of mass
“A given compound always contains exactly the same proportions of elements by mass” is which law?
Law of definite proportions
When two elements form a series of compounds, the ratios of the masses of the second element that combine with 1 gram of the first element can always be reduced to small whole numbers. What law is this?
Law of multiple proportions
Atoms with the same number of protons but a different number of neutrons are called what?
Isotopes
The # of protons + # of neutrons in the nucleus of that particular isotope is called what?
mass number (A)