Q2: Gen Bio Flashcards
father of atomism, focused on the ultimate components of all substances.
Believed that Matter is ultimately composed of indivisible particles, with nothing between them but empty space.
DEMOCRITUS (c.460-370 BC)
atoms Greek atomos, “”
uncuttable
held that it was impossible for “nothing” to exist, and his influence suppressed the concept of atoms for 2000 years.
ARISTOTLE (384-322 BC)
Further studies in the 18TH CENTURY gave rise to ______
laws concerning the relative masses of substances that react with each other.
- 2 mass laws discovered (law of mass conservation, law of definite proportions)
At the beginning of the 19TH CENTURY,______________
John Dalton proposed an atomic model that explained these mass laws.
Early 20TH CENTURY gave rise to ________________
a picture of the atom with a complex internal structure, which led to our current model.
matter having an invariant chemical composition and distinct properties
PURE SUBSTANCE
fundamental substance, cannot be separated into simpler substances by chemical methods
- Simplest type of matter with unique physical and chemical properties
- Consist of only one kind of atom
- Substance, matter whose composition is fixed
Element
Why are each element unique?
because the properties of its atoms are unique
Most elements exist in nature as ____
population of atoms
an independent structure consisting of 2 or more atoms chemically bound together.
molecules
substance composed of 2 or more elements in Fixed proportion; can be separated into simpler substances and elements only by chemical methods
- type of matter composed of two or more different elements that are chemically bound together.
Compound
consists of fixed numbers of atoms of the component elements.
Compound
T or F. properties of compounds are different from those of its component elements
T
What process do compounds undergo during its breakdown
Chemical change/Chemical process
matter consisting of 2 or more pure substances that retain their individual identities and can be separated by physical methods since they are physically intermingled
MIXTURE
T or F. components of a mixture don’t vary in their parts by mass.
F - components of a mixture can vary in their parts by mass.
T or F. A mixture retains many of the properties of its components.
T
Unlike compounds, mixtures can be separated into their components by________
by physical changes;
mixture having a uniform composition and properties throughout
- also called??
Homogeneous ; Solution
no visible boundaries because the components are mixed as individual atoms, ions, and molecules.
Homogeneous Mixture
T or F. We have no way to tell visually whether an object is a substance (element or compound) or a homogeneous mixture.
T
T or F. Solutions can only exist in the liquid state
F - can exist in all 3 physical states
mixture not uniform in composition and properties throughout.
Heterogeneous