Chapter 3.3 Flashcards
(18 cards)
The atomic number of an element is
The number of protons in each atom of the element
Hydrogen that is composed of atoms with two neutrons is called
Tritium
Isotopes are atoms of the same element that have different
Numbers of electrons
Mass number is
Protons+neutrons
The isotope uranium-235 has 92 protons and 143 neutrons. Therefore, its mass number is
235
The nuclear symbol for uranium-235 should be written as
235
U
92
What is the definition of one atomic mass unit
1/12 of the mass of a carbon-12 atom
One mole is defined as
the amount of a substance that contains as many particles as there are atoms in exactly 12 g of carbon-12
The molar mass of an elect is numerically equal to the elements
Average atomic mass
Atomic Number
The number of protons of each atom of that element
Isotope
Atoms of the same element that have different masses
Mass number
The total number of protons and neutrons that make nucleus
Nuclide
General term for the specific isotope of an element
Unified atomic mass unit
1/12 the mass of carbon-12 atom
Average atomic mass
The weighted average of the atomic masses of the isotopes of an element found in nature
Mole
The amount of a substance that contains as many particles as there are atoms in exactly 12g of carbon-12
Avogadro’s Number
The number of particles in exactly one mole of a pure substance.
6.022x10^23
Molar mass
The mass of one mole of a substance
