Answer:
B) conducts electricity
Explanation:
This answer can be answered by the process of elimination. Metals are excellent conductors of electricity, which means A is out, and metals are also known to have medium reactivity and have high melting points, meaning C and D are also out.
Answer : The standard enthalpy of formation of ethylene is, 52.4 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation reaction of
will be,

The intermediate balanced chemical reaction will be,
(1)

(2)

(3)

Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equation, we get :
(1)

(2)

(3)

The expression for enthalpy of formation of
will be,



Therefore, the standard enthalpy of formation of ethylene is, 52.4 kJ
<h3>
Answer:</h3>
251 mol Xe
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Atomic Structure</u>
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
<u>Stoichiometry</u>
- Using Dimensional Analysis
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
[Given] 1.51 × 10²⁶ atoms Xe
[Solve] moles Xe
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
- [DA] Set up:

- [DA] Multiply/Divide [Cancel out units]:

<u>Step 4: Check</u>
<em>Follow sig fig rule and round. We are given 3 sig figs.</em>
250.747 mol Xe ≈ 251 mol Xe
Answer:
Explanation:
The increase of the arable land has been affected partly by the reclamation of the marshes, but mostly by the transformation of large tracts of the puszta
An example of a reclamation is how landfill employees sift through garbage to find usable items. An example of a reclamation is trees growing on land that was heavily logged.