<u>Answer: </u>The correct statement is X is the effective nuclear charge, and it increases across a period.
<u>Explanation:</u>
We are given that:
X = number of protons − number of core electrons
Effective nuclear charge is defined as the actual nuclear charge (Z = number of protons) minus the screening effect caused by the electrons present between nucleus and valence electrons. These electrons are the core electrons.
The formula used for the calculation of effective nuclear charge given by Slater is:

where,
= effective nuclear charge
Z = atomic number or actual nuclear charge or number of protons
= Screening constant
The effective nuclear charge increases as we go from left to right in a period because nuclear charge increases with no effective increase in screening constant.
Hence, the correct answer is X is the effective nuclear charge, and it increases across a period.
First find the oxidation states of the various atoms:
<span>in Cr2O2 2- Cr @ +1; In NH3 N @ +3; in CrO3 Cr @ +3, N2 N @ 0 </span>
<span>Note that N gained electrons, ie, was reduced; Cr was oxidized </span>
<span>Now there is a problem, because B has NH4+ which the problem did not, and is not balanced, showing e- in/out </span>
<span>B.NH4+ → N2 </span>
<span>Which of the following is an oxidation half-reaction? </span>
<span>A.Sn 2+ →Sn 4+ + 2e- </span>
<span>Sn lost electrons so it got oxidized</span>
Answer:
The concentration of the murexide solution is 0.0000745 M
Explanation:
From Beer-Lambert's law,
A = εlc
A = Absorbance = 28.65% = 0.2865
ε = molar absorptivity = 3847 M/cm
l = path length = 1cm
c = concentration in mol/L = ?
c = A/εl = 0.2865/(3847×1) = 0.0000745 mol/L
Hope this Helps!
Answer:
B. Salt, NaCl, is produced by the process of evaporation of seawater or brine. If the surface area of the water is increased, the same volume of water evaporates faster.
C. The Haber process combines hydrogen and nitrogen to make ammonia. The two gases are passed through a reactor under pressure and at high temperatures. If iron is added to the reactor, the yield of ammonia increases.
Explanation:
Evaporation of water is responsible for the production of sodium chloride also known as table salt. Sodium and chlorine are present in water. When more evaporation of water occurs, sodium and chlorine come close together forming sodium chloride. Haber process is responsible for the production of ammonia which is used as fertilizer. For speed up the process, catalyst is used such as iron in order to complete the reaction in less time. Iron binds hydrogen and nitrogen with each other.
Answer:
two electrons.
Explanation:
Helium-5, like all other helium isotopes, has two protons and two electrons. Its different from the others in the fact that it has three neutrons. It is one of the unstable isotopes, having a half-life of significantly less than a picosecond (a trillionth of a second). your welcome!!