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MSU CEM 141 Questions And Answers Rated A+ New Update Assured Satisfaction
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MSU CEM 141 Questions And Answers Rated A+ New Update Assured Satisfaction
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MSU CEM 1414 Types of Forces - ANS-Gravitational, Electromagnetic, Strong Nuclear, Weak Nuclear
A compound - ANS-
A molecule can be made out of - ANS-two or more atoms of the same or different element
Absorption spectrum - ANS-
All neutral atoms and molecules attract each other - ANS-True
Amplitude - ANS-height of peaks (intensity)
An element X exists as diatomic molecules held together by 3 covalent bonds, while another
element Y exists as a 3D network of single covalent bonds. Element X has a higher atomic
mass than element Y. Which element is most likely to have the highest melting point? - ANS-Y,
because all the bonds in the 3D network must break for the substance to melt
Are electrostatic forces meditated by fields? - ANS-True
Are gravitational forces always attractive? - ANS-True
Are gravitational forces meditated by fields? - ANS-True
As the atoms get closer, which force is the strongest? - ANS-Electrostatic
As the atoms move even closer, which force is the strongest? - ANS-Repulsion
As the helium atoms approach what happens to the kinetic energy? - ANS-Increases
As the helium atoms approach what happens to the potential energy? - ANS-Decreases
As the helium atoms approach what happens to the total energy? - ANS-Stays the same
As two atoms approach, what is happening to the potential energy? - ANS-the potential energy
decreases because the atoms attract each other's temporary dipoles
As two helium atoms approach each other, the electrostatic force _________, causing the
potential energy to__________. - ANS-increases, decrease
,As you increase the frequency what happens to the wavelength? - ANS-The wavelength
decreases
At the potential minimum, which force is the strongest? - ANS-ES Attraction and ES repulsion
are balanced
Atomic # = - ANS-# of protons
Atomic absorption spectra are caused by.... - ANS-Electrons moving to higher energy levels and
absorbing photons of energy equal to the energy difference between the levels.
Atomic Force Microscopy/ Scanning Tunneling Microscopy - ANS-Microscopes that now allows
us to view atoms.
Atomic mass = - ANS-what's left over
Atomic Radius Decreases ----> Ionization energy increases - ANS-when the radius decreases, it
pulls the electrons closer. decreasing the size of an atom
Atoms - ANS-The smallest unit of an element
Big Bang evidence - ANS-universe is expanding (red shift)
Bonding in Diamond - ANS-each carbon atom is bonded to make more carbon atoms
Bonding in Graphite - ANS-one s and two p orbitals hybridize to give three Sp2 orbitals
Bonding in Metals - ANS-atomic orbitals combine with each other to form molecular orbitals
Breaking covalent bonds - ANS--Requires energy
-Electrons in the bond are attracted to two nuclei simultaneously
-The energy of the atoms when bonded is lower than the energy of the separate atoms
C = h x v - ANS-c = velocity (3.00 x 10^8 m s^-1 for light)
Can electrostatic forces be either attractive or repulsive? - ANS-True
CH4 + 2O2 ----> 2H2O +CO2
How many molecules of CH4 will remain at the end? - ANS-0
CH4 + 2O2 ----> 2H2O +CO2
How many molecules of CO2 will be produced? - ANS-3
, CH4 + 2O2 ----> 2H2O +CO2
How many molecules of H2O will be produced? - ANS-6
CH4 + 2O2 ----> 2H2O +CO2
How many molecules of O2 will remain at the end? - ANS-3
Changes of state (gas --> liquid --> solid) - ANS-RELEASES energy
Changes of state (solid --> liquid ---> gas) - ANS-REQUIRES energy
Chemical Reactions - ANS-• Involve rearrangements (sharing, donating
or accepting) of valence electrons
• The element undergoing a chemical
reaction does not change (EVER)
Chemical reactions - ANS-involve rearrangements of valence electrons
*the element undergoing a chemical reaction does not ever change*
Consider the isoelectronic (they all have the same number of electrons) species Na+, Mg2+,
Ne, and F-, which of these has the smallest radius? - ANS-Mg2+
All the species have the same number of electrons - but different number of protons. Mg2+ has
the highest proton to electron ratio and therefore the highest effective nuclear charge and the
strongest attraction between the protons and electrons - which pulls the electron cloud towards
the nucleus until the repulsions take effect.
Core electrons - ANS-
Coulomb's Law - ANS-Negative and positive charges attract and like charges repel.
Covalent Bonds - ANS-two hydrogen atoms interact and form a covalent bond
Covalent bonds hold atoms together within.. - ANS-molecules
Dipole-dipole Interactions - ANS--Present in polar substances (along with LDF)
-Typically stronger than LDF
Examples: HCL, CH3, CH2O,Ch3OCH3
Do electrostatic forces decrease as distance between the objects increase? - ANS-True
Do electrostatic forces require 2 or more objects? - ANS-True
Do gravitational forces increase as distance between the objects increase? - ANS-False
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