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3 years ago

Choose the element described by the following electron configuration.

Chemistry

2 answers:

Rufina [12.5K]3 years ago

6 0

Answer:

Argon.

Explanation:

It has atomic number of 18 and has a stable 8 electron outer shell.

Argon.

nadezda [96]3 years ago

4 0

Answer:

The answer to your question is Argon

Explanation:

Electron configuration given 1s² 2s² 2p⁶ 3s² 3p⁶

To find the element whose electron configuration is given, we can do it by two methods.

Number 1. Sum all the exponents the result will give you the atomic number of the element.

2 + 2 + 6 + 2 + 6 = 18

The element with an atomic number of 18 is Argon.

Number 2. Look at the last terms of the electronic configuration

3s² 3p⁶

Number three indicates that this element is in the third period in the periodic table.

Sum the exponents 2 + 6 = 8

Number 8 indicates that this element is the number 8 of that period without considering the transition elements.

The element with these characteristics is Argon.

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The octet rule states that atoms will gain, lose, or share valence electrons to get a full outer shell (orbital). Explain in you

bezimeni [28]

Answer:

In covalent bonding, the octet rule is important because sharing electrons gives both atoms a full valence shell. As a result, each atom can consider the shared electrons to be part of its own valence shell.

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6 0

2 years ago

Read 2 more answers

19. What is the density of a 16.39

slavikrds [6]

Density= mass/volume

16.39g/18.00mL = 0.9105 g/mL
Make sure to use the correct number of significant figures (4)

7 0

3 years ago

Two solutions namely, 500 ml of 0.50 m hcl and 500 ml of 0.50 m naoh at the same temperature of 21.6 are mixed in a constant-pre

weeeeeb [17]

24.6 ℃

<h3>Explanation</h3>

Hydrochloric acid and sodium hydroxide reacts by the following equation:

$\text{HCl} \; (aq) + \text{NaOH} \; (aq) \to \text{NaCl} \; (aq) + \text{H}_2\text{O} \; (aq)$

which is equivalent to

$\text{H}^{+} \; (aq) + \text{OH}^{-} \; (aq) \to \text{H}_2\text{O}\; (l)$

The question states that the second equation has an enthalpy, or "heat", of neutralization of $-56.2 \; \text{kJ}$ . Thus the combination of every mole of hydrogen ions and hydroxide ions in solution would produce $56.2 \; \text{kJ}$ or $56.2 \times 10^{3}\; \text{J}$ of energy.

500 milliliter of a 0.50 mol per liter "M" solution contains 0.25 moles of the solute. There are thus 0.25 moles of hydrogen ions and hydroxide ions in the two 0.500 milliliter solutions, respectively. They would combine to release $0.25 \times 56.2 \times 10^{3} = 1.405 \times 10^{4} \; \text{J}$ of energy.

Both the solution and the calorimeter absorb energy released in this neutralization reaction. Their temperature change is dependent on the heat capacity <em>C</em> of the two objects, combined.

The question has given the heat capacity of the calorimeter directly.

The heat capacity (the one without mass in the unit) of water is to be calculated from its mass and <em>specific</em> heat.

The calorimeter contains 1.00 liters or $1.00 \times 10^{3} \; \text{ml}$ of the 1.0 gram per milliliter solution. Accordingly, it would have a mass of $1.00 \times 10^{3} \; \text{g}$ .

The solution has a specific heat of $4.184 \; \text{J} \cdot \text{g}^{-1} \cdot \text{K}^{-1}$ . The solution thus have a heat capacity of $4.184 \times 1.00 \times 10^{3} = 4.184 \times 10^{3} \; \text{J} \cdot\text{K}^{-1}$ . Note that one degree Kelvins K is equivalent to one degree celsius ℃ in temperature change measurements.

The calorimeter-solution system thus has a heat capacity of $4.634 \times 10^{3} \; \text{J} \cdot \text{K}^{-1}$ , meaning that its temperature would rise by 1 degree celsius on the absorption of 4.634 × 10³ joules of energy. $1.405 \times 10^{4} \; \text{J}$ are available from the reaction. Thus, the temperature of the system shall have risen by 3.03 degrees celsius to 24.6 degrees celsius by the end of the reaction.