Chapter 1 Flashcards
(67 cards)
atoms or molecules have a lot of space between them. They are free to move relative to one another, making it compressible.
Gas
atoms or molecules pack about as closely as they do in solid matter, but they are free to move relative to each other.They have fixed volume but not a fixed shape.
Their ability to flow makes them assume the shape of their container.
Liquid
Atoms or molecules pack closely to each other in fixed locations. Although the atoms and molecules vibrate, they do not move around or past each other. Consequently, they have a fixed volume and rigid shape.
Solid
Matter can be classified according to
- It’s state
- It’s composition
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
anything that has mass and occupies space
Matter
the discipline that seeks to understand matter and its properties.
Chemistry
If a substance is a pure substance, it can be classified as either an ____ or a ________.
Element;compound
made up of only one component, and its composition is invariant.
Pure substance
A substance composed of two or more components in proportions that can vary from one sample to another.
Mixture
a substance that cannot be chemically broken down into simpler substances.
Element
substance composed of two or more elements in fixed definite proportions.
Compound
a process for understanding nature by observing nature and its behavior through experimentation.
Scientific method
one made of multiple substances, but it appears to be one substance. All portions of a sample have the same composition and properties (like sweetened tea).
Homogeneous mixture
one in which the composition varies from one region of the mixture to another. Made of multiple substances, whose presence can be seen (e.g., a salt and sand mixture)
Heterogeneous mixture
They are also known as data.They are the descriptions about the characteristics or behavior of nature.
Observations
a tentative interpretation or explanation of the observations.
Hypothesis
A brief statement that summarizes past observations and predicts future ones
Scientific law
Law that states, “in a chemical reaction, matter is neither created nor destroyed.” is known as
Law of conservation of mass
A well-established hypothesis or set of hypotheses form the basis for a scientific ____
Theory
Which statement best explains the difference between a law and a theory?
(a) A law is truth whereas a theory is mere speculation.
(b) A law summarizes a series of related observations, while a theory gives the underlying reasons for them.
(c) A theory describes what nature does; a law explains why nature does it.
(b) A law summarizes a series of related observations, while a theory gives the underlying reasons for them.
______ and _____ were the first to propose that matter was composed of small, indestructible particle
Leucippus;Democritus
________wrote, “Nothing exists except atoms and empty space; everything else is opinion.”
He proposed that atoms existed in different shapes and sizes and moved randomly through empty space
Democritus