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inna [77]
3 years ago
5

1. Which statement best explains why the elements in Group 18 do not have electronegativity values?(1 point)

Chemistry
2 answers:
Ratling [72]3 years ago
6 0

▪▪▪▪▪▪▪▪▪▪▪▪▪  {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪

The Correct choices are :

  • 1. The elements have filled valence levels.

  • 2. potassium (K) with a 1+ charge
pychu [463]3 years ago
4 0

Answer:

1. The elements have filled valence levels.

2. potassium (K) with a 1+ charge

Explanation:

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Marysya12 [62]
<span>Lemon juice has more acid because of its density and it contains more sodium.</span>
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Number of moles in 3.70 x 10^-1 g of boron
aleksley [76]
The answer is 10.81 g of boron.
8 0
4 years ago
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What is the nuclear binding energy of an atom that has a mass defect of 5.0446
notsponge [240]

Answer:

<em>Option C: 4.54 x </em>10^{11}<em> KJ/mol of nuclei</em>

<em>Note: </em>Here in this question option C is not correctly put. It is 4.54 x10^{11} rather than 4.54 x 10^{-123}.

Explanation:

If mass defect is known, then nuclear binding energy can easily be calculated, here's how:

First step is to convert that mass defect into kg.

Mass defect = 5.0446 amu

Mass defect = 5.0466 x 1.6606 x 10^{-27}

Because 1 amu = 1.6606 x 10^{-27} Kg.

<em>Mass defect = 8.383 x </em>10^{-27}<em> kg.</em>

Now, we need to find out it's energy equivalent by using following equation:

Using the equation E = mc²:

where c= 3.00 x 10^{8} m/s²

E = (8.383 x 10^{-27}) x (3.00 x 10^{8})²

E = 7.54 x 10^{-10} J  this energy is in Joules but nuclear binding energy is usually expressed in KJ/mol of nuclei. Let's convert it:

(7.54 x 10^{-10} Joule/nucleus)x(1 kJ/1000 Joule)x(6.022 x 10^{23} nuclei/mol) =  

<em>4.54 x </em>10^{11}<em> kJ/mol of nuclei .</em>

E = <em>4.54 x </em>10^{11}<em> kJ/mol of nuclei .</em> So, this is the nuclear binding energy of that atom, which is option  C.

<em>Note:</em> Here in this question option C is not correctly put. It is 4.54 x10^{11} rather than 4.54 x 10^{-123}

4 0
4 years ago
Read 2 more answers
4. What mass of urea is produced from 9.0 liters of ammonia?
lana [24]

Answer:

12.07 g.

Explanation:

  • The balanced equation for the mentioned reaction is:

<em>2NH₃(g) + CO₂(g) → H₂NCONH₂(g) + H₂O(g),</em>

It is clear that 2.0 moles of NH₃ react with 1.0 mole of CO₂ to produce 1.0 mole of H₂NCONH₂ and 1.0 moles of H₂O.

  • Consider the reaction proceeds at STP conditions:

At STP, 9.0 L of NH₃ react with an excess of CO₂ gas:

It is known that at STP: every 1.0 mol of any gas occupies 22.4 L.

<u><em>using cross multiplication:</em></u>

1.0 mol of NH₃ represents → 22.4 L.

??? mol of NH₃ represents → 9.0 L.

∴ 9.0 L of NH₃ represents = (1.0 mol)(9.0 L)/(22.4 L) = 0.4018 mol.

  • To find the no. of moles of urea (H₂NCONH₂) produced:

<u><em>Using cross multiplication:</em></u>

2.0 mol of NH₃ produce → 1.0 mol of H₂NCONH₂, from stichiometry.

0.4018 mol of NH₃ produce → ??? mol of H₂NCONH₂.

∴ The no. of moles of H₂NCONH₂ = (1.0 mol)(0.4018 mol)/(2.0 mol) = 0.201 mol.

  • Now, we can find the mass of H₂NCONH₂ produced:

<em>mass = n * molar mass</em> = (0.201 mol) * (60.06 g/mol) = <em>12.07 g.</em>

8 0
3 years ago
How does the law of conservation of matter apply to chemical equations?
Tasya [4]

Answer: option D.

The total number of atoms of each element on both sides of the

equation must be the same.

Explanation:

3 0
4 years ago
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