Answer:
Earthquakes are measured using instruments called seismometers, that detect the vibrations caused by seismic waves as they travel through the crust. Also, laser beams can be used
Explanation:
Radioactive material undergoes 1st order decay kinetics.
For 1st order decay, half life = 0.693/k
where k = rate constant
k = 0.693/half life = 0.693/8.02 = 0.0864 day-1
Now, for 1st order reaction,
k =

Given: t = 6.01d, initial conc. = 5mg
∴0.0864 =

∴ final conc. = 2.975 mg
Explanation:
both iron and sulphur in FeS2 undergo a change in oxidation state.
O2° -->2O degree2- Total decrease = 2×2=4
So, 4FeS2+11O2 --> 2Fe2O3+8 SO2
Hence, balanced
Answer:
The strength of a bond depends on the amount of overlap between the two orbitals of the bonding atoms
Orbitals bond in the directions in which they protrude or point to obtain maximum overlap
Explanation:
The valence bond theory was proposed by Linus Pauling. Compounds are firmed by overlap of atomic orbitals to attain a favourable overlap integral. The better the overlap integral (extent of overlap) the better or stringer the covalent bond.
Orbitals overlap in directions which ensure a maximum overlap of atomic orbitals in the covalent bond.
Answer:
%Ionization = 1.63%
Explanation:
Hydrazine in aqueous media theoretically forms a difunctional hydroxyl system. However, for this problem assume only monofunctional ionization occurs. A second hydroxyl ionization would not likely occur as the formal cationic charge formed in the 1st ionization would inhibit a second ionization.
H₂NNH₂ + 2H₂O => HONHNHOH => HONHNH⁺ + OH⁻; Kb = 1.3 x 10⁻⁶
So, assuming all OH⁻ and HONHNH⁺ are delivered in the 1st ionization then a good estimate of the %ionization can be calculated.
HONHNHOH => HONHNH⁺ + OH⁻
C(i) => 0.490M 0M 0M
ΔC => -x +x +x
C(eq) => 0.490 - x x x
≅0.490M* => *x is dropped as Conc H₂NNH₂/Kb > 100
Kb = [HONHNH⁺][OH⁻]/[HONHNHOH]
1.3 x 10⁻⁶ = x²/0.490
=> x = [OH⁻] = [HONHNH⁺] = √[(1.3 x 10⁻⁶)(0.490)] = 8 x 10⁻⁴
=> %Ionization = (x/0.490)100% = (8 x 10⁻⁴/0.490)100% = 1.63%