Ch 2 The Structure of Matter Flashcards
groups on the PTOE are:
vertical, 8, tell you the number of electrons in the outermost shell, groups act chemically the same
periods on the PTOE are:
horizontal, 7, tells you the maximum number of shells you can have (K-Q)
the K shell can only have __ electrons
2
the outermost shell can only have ___ electrons
8 or less
*the smallest part of an element is _____
an atom
Dmitri Mendeleev:
showed that elements in order of increasing atomic mass (A) created a repetition of similar chemical properties (1st PTOE)
Niels Bohr:
1913 created the solar system atom, electrons revolve around a nucleus in orbits, nucleus is positive, electrons are negative
*The fundamental particles of an atom are the:
electron, proton & neutron
1 atomic mass unit (amu) is equal to:
1/2 the mass of a carbon-12 atom
amu of an electron:
0
amu of a proton:
1
amu of a neutron:
1
*The atom is essentially:
empty space
the number of protons determines the:
chemical element
*In their normal state atoms are electrically:
neutral, their charge is 0
to eject an electron (to ionize an atom) from an atom you need ___
34 eV
*Ionization is:
the removal or addition of an orbital electron from an atom
the number of neutrons is always:
greater than the number of protons
*No outer shell can have more than__
8 electrons
*Centripetal force is:
“center seeking”, the force that keeps an electron in orbit
Centrifugal fore is:
“flying out from the center”, so electrons keep their distance from the nucleus, will kick an electron out
electron binding energy is:
the strength of attachment of an electron to the nucleus
atomic # is:
Z, number of protons, determines chemical behavior
atomic mass # is:
A, number of protons and neutrons
*The atomic mass number and the precise mass of an atom are:
not equal
*istoPe:
have the same number of PROTONS and same atomic number (Z), different mass and neutrons
*isobAr:
same ATOMIC MASS (A), different atomic number, neutrons, and protons but same number of nucleons total