So you don't jump off a cliff thinking you could fly. Laws and Motion are heavily used in jobs and help us understand more about the mechanics of how earth's gravity operates. Imagine in the future where we could manipulate gravity? That's why we learn and study this so much.
False- you have to have a hearing with a judge to see how long it is revoked for.
Answer:
B. PROTONS EXHIBIT STRONGER PULL ON OUTER f ORBITALS
Explanation:
Lanthanide contraction is the greater than normal decrease in the ionic radius of the lanthanide series from atomic number 57 to atomic number 71. This decrease is rather not expected of the ionic radii of these elements and they result in the greater decrease in the subsequent series of the lanthanides from the atomic number 72. The cause of which is as a result of the poor shielding effects of the nuclear charge around the electrons of the f orbitals. So therefore, protons are strongly pulled out of the 4f orbital and as a result of the poor shielding effect which causes the electrons of the 6s orbitals to be drawn more closer to the nucleus and hence resulting in a smaller atomic radii. It is worthy to note that the shielding effects of the inner electrons decreasing from s orbital to the f orbital; that is s > p > d > f. So from the decrease in the shielding effects from s to the f orbitals, lanthanide contraction results from the inability of the orbitals far away from s like the 4f orbiatls to shield the outermost shells of the lanthanide elements. So the cause of lanthanide contraction is the action of the protons which strongly pull the electrons of the f orbitals because of the poor shielding effects due to the distance of this orbital from the nucleus.
Explanation:
The net equation will be as follows.
So, we are required to find 
for this reaction.
Therefore, steps involved for the above process are as follows.
Step 1: Convert K from solid state to gaseous state
, 
= 89 kJ
Step 2: Ionization of gaseous K
, 
= 418 KJ
Step 3: Dissociation of 
gas into chlorine atom
.
, 
= 122 KJ
Step 4: Iozination of chlorine atom.
, 
= -349 KJ
Step 5: Add 
ion and 
ion formed above to get KCl
.
, 
= -717 KJ
Now, using Born-Haber cycle, value of enthalpy of the formation is calculated as follows.
= 89 + 418 + 122 - 349 - 717
= - 437 KJ/mol
Thus, we can conclude that the heat of formation of KCl is - 437 KJ/mol.
Boron: isotope data. Both isotopes ofBoron, B-10 and B-11, are used extensively in the nuclear industry. B-10 is used in the form of boric acid as a chemical shim in pressurized water reactors while in the form of sodium pentaborate it is used for standby liquid control systems in boiling water reactors
