Atoms and the Periodic Table Flashcards
(20 cards)
In an atomic model that includes a nucleus, positive charge is
concentrated in the center of an atom
Which subatomic particle has a negative charge?
electron
Which statement about subatomic particles is true?
An electron has far less mass than either a proton or neutron
Which of the following is unique for any given element?
the number of protons
The number of protons in one atom of an element is that element’s
atomic number
To find the number of neutrons in an atom, you would subtract
mass number from atomic number
What does the electron cloud model describe?
the most likely locations of electrons in atoms
How many protons does an atom with an atomic number of 23 and a mass number of 51 have?
28
An atom has no overall charge if it contains equal numbers of
electrons and protons
Which statement about protons is true?
Protons are part of the nucleus of an atom.
An atom of gold with 79 protons, 79 electrons, and 118 neutrons would have a mass number of
197
Which of the following has the LEAST mass?
Electron
The smallest particle into which an element can be divided and still be the same substance is a(n)
Molecule
Atoms are composed of
electrons, protons, and neutrons
What particles make up a nucleus?
Protons and neutrons
The SI unit used to express the masses of particles in atoms is the
atomic mass unit (amu).
What is the atomic number of this iron atom?
26
What is the mass number of this iron atom?
54
Which group contains the most elements?
metals
In an atom, the number of protons equals the number of
electrons
