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
Sulfur-34 (atomic number 16) contains
18 neutrons
Neon-22 contains 12 neutrons it also contains
10 protons
Calcium-48 (atomic number 20) contains
20 electrons
PEZ means
Protons electrons and atomic number are all the same
T or F mass number is the same as atomic number
False
The carbon-12 atom is assigned a relative mass of exactly
12 amu
Two oxides of lead, PbO and PbO2 are explained by the
Low of multiple proportions
Principled of atomic theory recognized today were conceived by
Dalton
T or F atoms of the same element may have different masses
True
The discovery f the electron resulted from experiments using
Cathode rays
In Rutherfords experiment most of the particles
Passes through the foil
Rutherfords experiments led to the discovery of the
Nucleus
Protons have
An attraction for neutrons
The charge on the electron cloud
Balances the charge on the nucleus
All isotopes of hydrogen contain
One proton
Nickel-60 (atomic number 28) has
32 neutrons
T or F neutrons of negatively charged
False
Atoms of the same element with different number of neutrons
Isotopes
When writing nuclear symbol notation, what’s on top? Bottom?
Mass number on top
Atomic number on bottom
Transition elements are all
Metals
Bottom row consists of
Inner transition elements
Ions that have a positively charge
Cations
Ions that have a negatively charge
Anions
Form when a atom loose electrons
Cations
Forms when a atom gains electrons
Anions
Ions with opposite charges attract
Ionic compound
Named by changing the ending of the name to
Ide
Mass is neither created nor destroyed during regular chemical or physical changes
L’s of conservation of mass
Any amount of a compound contains the same element in the same proportions by mass
Lw of definite proportions
Applies when 2 or more elements combine to make more than one type of compound
Lw of multiple proportions
