1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Vlada [557]
2 years ago
12

Which isotope of lead has a double magic number? (1) Pb-206 (2) Pb-207 (3) Pb-208 (4) Pb-209

Chemistry
1 answer:
antiseptic1488 [7]2 years ago
4 0
It is Pb-208, answer 3.
You might be interested in
Find δs∘ for the reaction between nitrogen gas and hydrogen gas to form ammonia:12n2(g) 32h2(g)→nh3(g)
Dima020 [189]

Nitrogen (N2) and hydrogen (H2) gases react to form ammonia, which requires -99.4 J/K of standard entropy (ΔS°).

What is standard entropy?

The difference between the total standard entropies of the reaction mixture and the summation of the standard entropies of the outputs is the standard entropy change. Each entropy in the balanced equation needs to be compounded by its coefficient, as shown by the letter "n."

Calculation:

Balancing the given reaction following-

1/2 N₂(g) + 3/2 H₂ (g)→ NH₃ (g)

ΔS° = [1 mol x S° (NH₃)g] - [1/2 mol x S° (N₂)g] - [3/2 mol x S°(H₂)g]

Here S° = standard entropy of the system

Insert into the aforementioned equation all the typical entropy values found in the literature:

ΔS° = [1 mol x 192.45 J/mol.K] - [1/2 mol x 191.61 J/mol.K] - [3/2 mol x 130.684 J/mol.K]

⇒ΔS° = - 99.4 J/K

Therefore, the standard entropy, ΔS° is -99.4 J/K.

Learn more about standard entropy here:

brainly.com/question/14356933

#SPJ4

5 0
1 year ago
When heat move in a gas or liquid, warm matter rise and cold matter sinks, creating currents. which type of heat transfer is thi
ch4aika [34]
I believe it is convection
6 0
2 years ago
A 34.53 ml sample of a solution of sulfuric acid, h2s04, reacts with 27.86 ml of 0.08964 m naoh solution. calculate the molarity
Gnoma [55]
The balanced equation between NaOH and H₂SO₄ is as follows
2NaOH + H₂SO₄ ---> Na₂SO₄ + 2H₂O
stoichiometry of NaOH to H₂SO₄ is 2:1
number of moles of NaOH moles reacted = molarity of NaOH x volume
number of NaOH moles = 0.08964 mol/L x 27.86 x 10⁻³ L = 2.497 x 10⁻³ mol
according to molar ratio of 2:1
2 mol of NaOH reacts with 1 mol of H₂SO₄
therefore 2.497 x 10⁻³ mol of NaOH reacts with - 1/2 x 2.497 x 10⁻³ mol of H₂SO₄
number of moles of H₂SO₄ reacted - 1.249 x 10⁻³ mol 
Number of H₂SO₄ moles in 34.53 mL - 1.249 x 10⁻³ mol 
number of H₂SO₄ moles in 1000 mL - 1.249 x 10⁻³ mol / 34.53 x 10⁻³ L = 0.03617 mol 
molarity of H₂SO₄ is 0.03617 M
6 0
3 years ago
Several properties of water are shown. Classify each property as a physical property or a chemical property.
34kurt

Chemical property:

  • Can be split into hydrogen and oxygen
  • Reacts with certain metals

Physical property:

  • Is liquid at room temperature
  • Has a density of 1.0 g/cm³
7 0
2 years ago
The density of solid ni is 8.90 g/cm3. how many atoms are present per cubic centimeter of ni
bulgar [2K]
Density gives mass of object per volume......   Here, density is given 8.90 g/cm3   therefore, per cubic centimeter contains 8.90 g Ni.   mole of Ni = mass / atomic mass   = 8.90 / 58.6934   = 0.1516 mole     number of atoms: mole * 6.022 * 10^23   = 0.1516 * 6.022 * 10^23   = 0.9129 * 10^23   = 0.9 * 10^23 (approx.)
7 0
3 years ago
Other questions:
  • Is the following sentence true or false? the mass of an object changes with location.
    7·1 answer
  • I HAVE TIME LIMIT I NEED CORRECT ANSWERS!
    7·1 answer
  • I2 + Na2S2O3 → NaI + Na2S4O6 Balance the equation, if necessary.
    15·2 answers
  • Sulfurous acid, H2SO3, breaks down into water (H20) and sulfur dioxide (SO2).
    9·1 answer
  • How many moles are in 25.58 grams of H20? SHOW WORK
    8·1 answer
  • What kind of reaction is CO2=C+O2
    12·1 answer
  • Which are exmaples of chemical change?
    9·1 answer
  • How does an ecosystem benefit when leaves fall from a tree and decompose on the soil?
    11·2 answers
  • Does anyone know this? help please
    11·1 answer
  • Differentiate between volumetric analysis and titrimetric analysis ​
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!