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REY [17]
3 years ago
8

Which of these pairs of elements have the same number of valence electrons?

Chemistry
2 answers:
Ymorist [56]3 years ago
8 0
Those with the same number valence electrons would have to be in the same group in the periodic table.So answer is:

<span>Beryllium (Be) and Calcium (Ca)</span>

MA_775_DIABLO [31]3 years ago
4 0

Answer: Option (b) is the correct answer.

Explanation:

Valence electrons are the electrons which are present in outermost shell of an atom.

So, number of valence electrons of given elements will be as follows.

Phosphorous (P) - atomic number is 15, valence electrons are 5.

Chlorine (Cl) - atomic number is 17, valence electrons are 7.

Beryllium(Be)  - atomic number is 4, valence electrons are 2.

Calcium (Ca) - atomic number is 20, valence electrons are 2.

Helium (He) - atomic number is 2, valence electrons are 0.

Oxygen (O) - atomic number is 16, valence electrons are 6.

Carbon (C) - atomic number is 6, valence electrons are 4.

Therefore, we can conclude that berylium (Be) and calcium (Ca) is the pair of elements that have the same number of valence electrons.

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When bonding atoms seek to achieve a stable
Ronch [10]

Answer:

a stable octet state

Explanation:

a stable octet state is when all the energy levels of the atoms are filled with electrons and they are stabe

6 0
3 years ago
Hydrogen cyanide, HCN, is prepared from ammonia, air, and natural gas (CH₄), by the following process:
kykrilka [37]

Answer:

6.75 g of HCN can be produced by the reaction

Explanation:

Complete reaction is:

2NH₃ (g) + 3O₂ (g) + 2CH₄ (g) → 2HCN (g) + 6H₂O (g)

Let's determine the moles of each reactant:

11.5 g . 1mol / 17g = 0.676 moles of ammonia

12 g . 1 mol / 32g = 0.375 moles of oxygen

10.5 g . 1mol/ 16 g =  0.656 moles of methane

Now is all about rules of three:

2 moles of ammonia reacts with 3 moles of O₂ and 2 moles of methane

0.676 moles of NH₃ may react with:

(0.676 . 3) /2 = 1.014 moles of O₂

(0.676 . 2) / 2 = 0.676 moles of methane

Both can be the limiting reactant.

3 moles of O₂ react with 2 moles of NH₃ and 2 moles of methane

0.375 moles of O₂ will react with:

(0.375 .2) / 3  = 0.375 moles

The same amount for methane, 0.375 moles

2 moles of CH₄ reacts with 3 moles of O₂ and 2 moles of NH₃

0.656 moles of methane would react with 0.656 moles of NH₃

(0.656 . 3 ) /2 = 0.437 moles of O₂   I do not have enough O₂

Oxygen is the limiting reactant → We can work with the reaction now.

Ratio is 3:2. 3 moles of oxygen produce 2 moles of cyanide

0.375 moles of O₂ may produce (0.375 .2 ) / 3 = 0.250 moles

If we convert the moles to mass → 0.250 mol . 27 g / 1mol = 6.75 g

4 0
3 years ago
Consider the nuclear equation below. Superscript 22 subscript 11 upper N a right arrow superscript 22 subscript 10 upper N e plu
natali 33 [55]

Answer:

+1

Explanation:

For the equation to be balanced, the total mass number and the total atomic number on both side of the equation but be equal.

This is illustrated:

For the mass number:

Left side: 22

Right side: 22 + 0 = 22

For the atomic number:

Left side: 11

Right side: 10 + x

11 = 10 + x

Collect like terms

x = 11 - 10

x = 1

See attachment for further explanation.

8 0
3 years ago
Read 2 more answers
deduce the formula of the compound that contains 2+ ions and 3- ions that both have the same electron configuration as argon
yanalaym [24]

\\ \sf\longmapsto [Ar]

  • 2+ means

\\ \sf\longmapsto [Ar]^{2-}

  • The element will be Calcium

And

\\ \sf\longmapsto [Ar]^{3+}

  • The element will be Phosphorus
8 0
3 years ago
Which of the given statements best represent what to do in the event of a spill of concentrated sulfuric acid.
olga_2 [115]
D is the best answer !! good luck
4 0
2 years ago
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