Chapter 1 Classification Theories And Laws, Composition, Flashcards
Chemistry is the study of what
COMPOSITION  of substances and the changes they undergo
Scientific approach to solving problems equals what
Observation
Hypothesis
Experiment
New observation
Hypothesis
Experiment
What is a theory?
EXPLANATION of a phenomenon or event, based on a lot of experimental evidence
What is a scientific law?
A statement based on a lot of experimental evidence
A law STATES BUT DOESN’T EXPLAIN
It’s always true there are no exceptions as in hypothesis or theory
Matter is what
Anything that has mass and takes up space
All matter is made up of what?
Tiny particles called atoms
What are the two types of matter?
Or how do chemists, classify matter
Pure substance or mixture
What are the types of pure substances?
Elements or compounds
What are the types of mixtures?
Homogeneous or heterogeneous. Homogeneous his one phase heterogeneous is two phases.
What are the states of matter
Solid liquid gas
What are the defining characteristics of a solid?
Fixed shape and volume not compressible has upper surface
What are the defining characteristics of a liquid?
Varying shape, conforms to the shape of container, fixed volume, has upper surface, moderately compressible
What are the defining characteristics of a gas?
No fixed shape or volume
no upper surface
highly compressible
Use kinetic theory to describe behavior of three common states of matter?
In a solid particle, stay in one spot and vibrate,
in a liquid particles, move over and around their neighbors, but stay close together,
in a gas particles have enough energy to completely separate. They are approximately 1000 times farther apart, and they would be in a solid or liquid state.
What is amorphous?
Without shape or form such as plastic
What is Crystaline?
Particles that form regular repeating three dimensional geometric patterns
Such as salt salt
Describe homogeneous
No visible boundary between components
Describe heterogeneous
Visible boundary between components. Such as a settling at the bottom of the container or a salad.
What is a compound?
A pure substance composed of two or more elements, CHEMICALLY combined in a DEFINATE proportion
Is a pure substance homogeneous
Yes, but it is not a mixture
What is a phase?
Homogeneous part of a system separated from other parts by physical boundaries
What is a system?
A body of matter, under consideration
What are physical properties?
Properties of a substance shows by itself, without interacting with another substance, such as color, melting, point, boiling point density
What are chemical properties
Properties of substance shows as it interacts with, or transforms into other substances, such as flammability and corrosiveness
What are separation techniques? There are five.
Filtration, crystallization, distalization extraction, and chromotography
F
E
C
C
D
What is filtration?
It’s based on particle size
What is crystallization separation technique?
Separation based on a difference in Salyu ability and components in a mixture
What is distillation?
Separation based on differences in volatility
What is extraction
Separation based on differences in solubility in different solvents
What is chromatography?
Separation based on differences in solubility in a solvent versus a stationary phase
What is uniform in appearance and has the same properties throughout?
Homogeneous
Matter consisting of two or more physically, distinct phases, is what
Heterogeneous
What is a homogeneous part of a system separated from other parts by physical boundaries?
Phase
What is a body of matter? Under consideration?
A system
Explain a proton
Positively charged, heavy and large
Explain a neutron
Neutral charge, same size as proton
Explain an electron
Same quantity of charge as a proton, but opposite and
very small and nearly no mass
What subatomic particles are responsible for chemical properties of an element?
Electrons
The nucleus is held together by what
Nuclear force
In an element what is extremely stable and doesn’t change easily?
Protons, though electrons can change easily
What serves as a buffer between protons
Neutrons. Sometimes, with a different number of neutrons in the element may also be stable.
