Answer:
Most positive = rubidium
Most negative = fluorine
Explanation:
Electron affinity of an element is the energy released when an electron is attached to a neural atom to form an ion in its gaseous state.
X + e⁻ → X⁻
Electron affinity is similar to electronegativity which is the tendency at which an atom accepts an ion towards itself.
Electron affinity increases across the period and decreases down the group in the periodic table.
In the above option,
Fluorine has the highest electron affinity
Rubidium has the lowest electron affinity
Tellurium and then finally Phosphorus
Helium in this case would have the lowest electron affinity because it has filled orbital and does not require any electron to attain stability. Technically, Helium has the lowest or is expected to have the lowest electron affinity which is close to zero according to quantum mechanics.
Most positive = rubidium
Most negative = fluorine.
You can check periodic table for their exact values
Answer:
D. Solid state
Explanation:
In solid state the particles of a substance, vibrate in fixed positions though they posses less kinetic energy. This is the reason as to why the particles do not move far apart from each other making the solids remain in fixed shapes unless an extra energy is added.
A polar bond is formed with atoms having different electronegativities. The bonding electrons are attracted more towards the atom with greater electronegativity resulting in unequal sharing of electrons. Therefore the molecule develop partial charges and becomes polar. Polar molecules have dipole moment that is the partial charge on molecules due to differences in electronegativity between atoms.
A non-polar bond is formed with atoms having the same electronegativity, hence the bonded pair of electron is shared equally between atoms. Non-polar molecules have no moment.
Note that: symmetrical molecules having polar bonds are non-polar because the dipoles of the bond exert equal and opposite effect. Hence the dipoles cancel the charges.
Example: HCl
In HCl, Cl is more electronegative therefore Cl atom pulls the electron pair of the covalent bond towards itself and develops a partial negative charge. Consequently H develops a partial positive charge. This therfore leads to the formation of a dipole.
Answer:
(NH4)2S(aq) + Pb(NO3)2(aq) --> 2NH4NO3 (aq) + PbS (s)
The answer:
we should know the meaning of each abbreviation:
ms means millisecond, its value is 10^-3 s
ns means means nanosecond, its value is 10^-9 s
ps means picosecond, its value is 10^-12 s
fs means femtosecond, its value is 1x 10^15 s
<span>Expressions of the quantity 556.2 x 10^-12 are</span>
556.2 x 10^-12 =556.2 ps
556.2 x 10^-12 =556.2 x 10^-9 x 10^-3= 556.2 x 10^-9 ms
556.2 x 10^-12 = 556.2 x 10^-3 x 10^-9 = 556.2 x 10^-3 ns
556.2 x 10^-12 = 556.2 x 10^- 27 x 10^15 = 556.2 x 10^- 27 fs