Which is an example of an atom?

Given these reactions, where X represents a generic metal or metalloid 1) H2(g)+12O2(g)⟶H2O(g)ΔH1=−241.8 kJ 1) H2(g)+12O2(g)⟶H2O

Bond [772]

Answer:

ΔH = -793,6 kJ

Explanation:

It is possible to obtain ΔH of this reaction using Hess's law that says you can sum the half-reactions ΔH to obtain the ΔH of the global reaction:

If half-reactions are:

1) H₂(g) + ¹/₂O₂(g) ⟶ H₂O(g) ΔH₁ = −241.8 kJ

2) X(s) + 2Cl₂(g) ⟶ XCl₄(s) ΔH₂ = +356.9 kJ

3) ¹/₂H₂(g) + ¹/₂Cl₂(g) ⟶ HCl(g) ΔH₃ = −92.3 kJ

4) X(s) + O₂(g) ⟶ XO₂(s) ΔH₄ = −639.1 kJ

5) H₂O(g) ⟶ H₂O(l) ΔH₅ = −44.0 kJ

The sum of (4) + 4×(3) - (2) - 2×(1) - 2×(5) is:

(4) X(s) + O₂(g) ⟶ XO₂(s) ΔH = −639.1 kJ

+4×(3) 2H₂(g) + 2Cl₂(g) ⟶ 4HCl(g) ΔH = −369,2 kJ

-(2) XCl₄(s) ⟶ X(s) + 2Cl₂(g) ΔH = -356,9 kJ

-2×(1) 2H₂O(g) ⟶ 2H₂(g) + O₂(g) ΔH = +483,6 kJ

-2×(5) 2H₂O(l) ⟶ 2H₂O(g) ΔH = +88.0 kJ

= <em>XCl₄(s) + 2H₂O(l) ⟶ XO₂(s) + 4HCl(g)</em>

Where ΔH is:

ΔH = -639,1 kJ -369,2 kJ -356,9 kJ +483,6 kJ +88,0 kJ

I hope it helps!

5 0

3 years ago

The element carbon exists in several different forms. Pure carbon can be found in the form of diamonds, coal, and the graphite i

UNO [17]

Answer:

B) All carbon atoms have 6 neutrons.

Explanation:

The false statement from the given choices is that all carbon atoms have 6 neutrons.

There is a phenomenon called isotopy in chemistry.

Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.

These atoms of elements are called isotopes.
Carbon atoms generally have proton number of 6 which is the same as the atomic number.
As with all atoms, the mass number or atomic mass equals the number of protons and neutrons.

For the isotopes of carbon, their number of neutrons differs.

For example:

The number of neutrons differs in the above isotopes.

Number of neutrons = mass number - atomic number;

¹²₆C , number of neutrons = 12 - 6 = 6

¹³₆C, number of neutrons = 13 - 6 = 7

¹⁴₆C, number of neutrons = 14 - 6 = 8

Therefore, based on the concept of isotopy, all carbon atoms do not have 6 neutrons.

7 0

3 years ago

Which is a base unit used in the metric system?

DaniilM [7]

Answer:

<h2> Quarts </h2><h2>Litres </h2><h2>Pints </h2><h2>Degrees Fahrenheit. </h2>

ASK for more

4 0

3 years ago

Cracking the periodic table code why aren't the elements listed in alphabetical order answer key

finlep [7]

The elements in the periodice table are not listed in alphabetical order, because the arragement in rows (periods) and columns (groups or familes), in increasing order of atomic number (number of protons of the atoms) permits to explain similarities among the elements, trend in some properties, and even predict properties of unknown elements.

For example, the elements of the first group (family), called alkaline metals, all have 1 valence electron, have similar physical properties (ductibility, malleability, luster, thermal and electricity conductivity), react in similar way with water, show a trend in the atomic radii and in the ionization energy.

You can tell similar stories for other groups like, alkalyne earth metals, halogens and noble gases.

You can also tell trends in electroneativities, and atomic radii, for a row of elements, as per the order they are in the row.

So, the current array resulted very helpul for chemists to explain and predict the behavior and properties of the elements.

4 0

3 years ago

Read 2 more answers

- a) write the formula unit of calcium fluoride.

san4es73 [151]

Answer:

Practice

Look at the pictures and write about Faris's day. Use time words

35words 40words * 50 words ***

TUD

Writing checkout

Olused capital letters at the beginning of sentences. Olsusea finger espace between e

the pictures (I will describe it by words)first picture the boy returns from school the sec picture is I return and eat with the family and the third picture is I played with my sister and the fourth is I watch TV with my siblings and the last picture is I take the book and study ,in order write a story using this pictures that I describe it.

6 0

3 years ago