Chemistry Chap 3 Test
Terms
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- atomic mass unit
- a unit of mass that is exactly 1/12 the mass of a carbon-12 atom, or 1.660540 X 10^-27
- atomic number
- the number of protons in the nucleus of each atom of an element
- average atomic mass
- the weighted average of the atomic masses of the naturally occuring isotopes of an element
- Avogadro's number
- 6.022 X 10^23; the number of particles in exactly one mole of a pure substance
- isotopes
- atoms of the same element that have different masses
- mass number
- the total number of protons and neutrons in te nucleus of an isotope
- molar mass
- the mass of one mole of a pure substance
- mole
- the amount of a substance that contains as many particles as there are atoms in exactly 12g of carbon-12
- nuclide
- the general term for any isotope of any element; another term for an atom that is identified by the numer of protons and neutrons in its nucleus
- law of conservation of mass
- mass is neither created nor destroyed during ordinary chemical or physical reactions
- law of definite proportion
- a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the same or the source of the compound
- law of multiple proportions
- if two or more different compounds are composed of the same 2 elements. then the ratio of the masses of the 2nd element combined with a curtain mass of the first element is always a ratio of small whole numbers
- atom
- the smallest particle of an element that retains the chemical properties of that element
- nuclear forces
- these short-range proton-neutron, proton-proton, and neutron-neutron forces hold the nuclear particles together
- The word atom comes from a Greek word that means..
- unable to be divided
- The first person who suggested that matter was made up of atoms
- Democritus
- John Dalton's atomic theory
- atoms of the same element are exactly alike
- the nucleus of an atom has a ____ ________ charge
- positive electric charge
- where are neutrons and protons found
- in the nucleus of an atom
- atoms have equal numbers of
- protons and electrons
- according to modern atomic theory, the location of _____ is uncertain
- electron
- Isotopes of an element have the smame________ but different _____________
- atomic number, atomic mass
- an atom of potassium has an atomic mass of 39 amu and an atomic number of 19. ____ neutrons
- 20
- an element's average atomic mass refers to the weighted average of the masses of all its naturally occuring
- isotopes
- the lightest hydrogen isoptope and most commonly occuring
- protium
- the Si unit used for counting small particles, such as atom
- mole
- what of one mol of a substance equals its molar mass
- the mass in grams
- the number of particles in one mole of a substnace
- avogadro's number
- in cathode ray tubes, the cathode rat is emitted from the negative electrode, called the ______
- cathode
- the smalles unit of an elemnt that can exist either alone of in combination with atoms of the same or different elements
- atom
- a positively charged particle found in the nucleus is called
- proton
- a nuclear particle that has no elextrical charge is called a
- neutron
- the subatomic particles that are least massive and most massive, respectively, are the
- electron and neutron
- the amount of substance that containst the same number of atoms as 12g of carbon-12
- mole
- an atoms atomic numer is equal to
- its number of protons
- an toms mass number is determined by
- adding its protons and neutrons
- two atoms that have the same number of protons but different numbers of neturons are called
- isotopes
- Avogadros number states that one mole of a pure substance contains
- 6.022X 10^23 atoms
- first suggested the idea of atoms
- Democritus
- Identified the electron
- thomson
- calculate dmass of electron
- millikan
- discovered the nucleus
- rutherford
- discovered proton
- rutherford
- discovered neutron
- chadwick
- electron-- symbol, location, and electrical charge
- e- surrounding are of nucleus, negative
- neutron- symbol, loc, and charge
- n^o nucleus, neutral
- proton - symbol, loc, and charge
- p^+ nucleus, positive
- thomson model
- plum pudding, nucleus outside
- dalton model
- big black circle
- rutherford
- circle and inside it has surounding electrons, positive nucleus with 3 plus's
- the number of neutrons in an atom is reffered to as its atomic number (T F)
- F- number of protons
- the periodic table is arranged by increasing atomic number
- T
- Atomic number is equal to the number of electrons in the atom
- F- numer of protons
- The numer of protons in an atom identifies it as an atom of a particular element
- T
- Most atoms have either a positive or a negative charge
- F
- the mass of an electron is
- smaller than the mass of a proton, smaller than the mass of a neutron, a tiny fraction of the mass of an atom
- one atomic mass unit is
- 1/12 the mass of a carbon-12 atom
- the atomic mass of an atom is usually not a whole number because it accounts for
- both the relative abundance and the mass of each of the atom's isotopes
- the atomic number of oxgen ,8,indicates that there are eight
- protons in the nucleus of an oxygen atom
- the number that is the total number of protons and neutrons in the nucleus of an atom is the
- mass number
- isotopes of a particular element differ in
- the number of neutrons in the nucleus
- in determing atomic mass units, the standard is an
- C-12 atoms
- the chemical shorthand for atomic mass units
- amu
- the average atomic mass of an element is the weighted average of atomic masses of the
- naturally occurring isotopes
- because isotopes have differnt masses, they differ in their chemical behavior
- FALSE
- the mass number and the relative atomic mass of a given nuclide are close in value
- true
- the percentage of each isotope in the naturally occurring element differs in various places on Earth
- false
- the average atomic mass of an element depends on bothe mass and abundance of each element's isotopes
- true
- the elements on the periodic table of elements are listed in the order of atomic number
- true
- schoolteacher who studied atoms and proposed an atomic theory
- john dalton
- according to Dalton's atomic theory, atoms
- of a particular element are identical in size, mass, and other properties
- one part of Daltons atomic theory that has been modified is the idea that
- atoms cannot be subdivided
- daltons atomic theory did not explain
- conservation of energy
- the law of definite composition
- was explained by Dalton's atomic theory
- the fact that lead forms two oxides of different formulas, PbO and Pb0 ^2 is an example of the
- law of multiple proportions
- the center of an aotm contains positively charged ________ as well as neutral particles called __________
- protons, neutrons
- surrounding the center of the atom is a region occupied by electrons. electrona re
- identical negatively charged particles
- the paddle wheel experiment shows that
- the cathode ray has enough mass to perform work
- Rutherford's model of the atom suggests that
- an atom has a great deal of empty space