Chapter 4 Flashcards
Didn’t believe in atoms
Thought matter was continuous
Aristotle
Means indivisible
Atom
Mass is neither created or destroyed during regular chemical or physical changes
Law of conservation of mass
Any amount of a compound contains the same element in the sans proportions by mass
Law of definite proportions
Applies when 2 or more elements combine to make more than one type of compound
Lw of multiple proportions
T or F all atoms of a given element are identical
True
T or F atoms are not divisible into smaller particles
False. Subatomic particles
T or F atoms of the same element can have different mass isotopes
True
T or F atoms aren’t indivisible by chemical processes
False they are
Law of conservation of mass follows from the concept that
Atoms are indivisible
Which concept in Dalton’s atomic theory has been modified?
Atoms cannot be divided
Experiments with cathode rays led to the discovery of the
Electron
Whose experiment bombarded gold foil with positively charged particles and noted that some particles were widely deflected
Rutherford
Discovered the nucleus
Rutherford
J. J. Thompson discovered
The electron
Positively charged particle is
Proton
Not true about the nucleus of an atom is that
It contains nearly all of the atoms volume
An atom is electrically neutral because
The number of protons and electrons are equal
Atoms of the same element that have different masses are called
Isotopes
In determining atomic mass units, the standard is the
C-12 atom
An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. It’s mass number is
27
To find mass number
Add protons and neutrons
To find neutrons
Subtract mass number from protons
An atom of potassium has 19 protons and 20 neutrons mass number?
39
