Ionic compounds form ________ from a repeating pattern of ions.

The model of a “sea of electrons” helps explain ____.

andriy [413]

Answer:

The correct answer is C.) metallic bonds

Explanation:

Metallic bonds are formed between metal compounds and are very strong. These links are explained by the "sea model of electrons", where valence electrons are ceded by each metal atom, becoming positive ions forming a three-dimensional crystalline network. These electrons move forming a network ("sea") that allows the union of the positive ions formed.

3 0

3 years ago

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In an aqueous chloride solution cobalt(ii) exists in equilibrium with the complex ion cocl42-. co2 (aq) is pink and cocl42-(aq)

liraira [26]

First you should know that the Principle of Le Chatelier states that if a system in equilibrium is subjected to a change of conditions, it will move to a new position in order to counteract the effect that disturbed it and recover the state of equilibrium.

The variation of one or several of the following factors can alter the equilibrium condition in a chemical reaction:

Temperature
The pressure
The volume
The concentration of reactants or products

1. This reaction is: a. exothermic

The chemical equilibrium at issue is:

CoCl₄²⁻ ⇄ Co²⁺ + 4Cl⁻ + heat

blue pink

The reaction of the question is exothermic because when adding heat (at high temperature) the equilibrium moves to the left since the blue color is strong which means that there are more reagent (CoCl₄²⁻) that product (Co²⁺). On the other hand, when extracting heat from the system (at low temperature) the equilibrium moves to the right since the pink color predominates and more product is present in the solution.

2. When the temperature is decreased the equilibrium constant, k: c. remains the same.

As mentioned above, a system in equilibrium that is disturbed will move to a new position in order to counteract the effect that disturbed it and recover the state of equilibrium. In this way, the system will always remain in equilibrium and its equilibrium constant will remain constant. This is why, despite altering the temperature of the system, the equilibrium constant remains constant.

3. When the temperature is decreased the equilibrium concentration of Co²⁺: a. increases

Again, the chemical equilibrium at issue is:

CoCl₄²⁻ ⇄ Co²⁺ + 4Cl⁻ + heat

As the reaction in question is exothermic when the temperature decreases, heat is extracted from the system. To compensate this decrease in heat, the system will react by shifting the balance to the right, increasing the concentration of the products and, therefore, the concentration of Co²⁺.

5 0

4 years ago

Acetone major species present when dissolved in water

jek_recluse [69]

Answer: acetone molecule ( CH₃-CO-CH₃)

Explanation:

1) Acetone is CH₃-CO-CH₃

2) That is a molecule (build up of covalent bonds).

3) When dissolved, covalent bonded compounds remain as separate molecules, then it is said that the major species present in the solution is the molecule. The molecules of acetone are surrounded (sovated) by the molecules of water.

This as opposed to the case of ionic compounds that ionize. When a compound as NaCl dissolves in water, it ionizes completely, so the major speceies are not NaCl formulas, but the ions Na⁺ and Cl⁻, not molecules.

That leads to the answer: the major species present when acetone is dissolved in water is the molecules of acetone (you do not need to state the fact that the molecules of water are part of the solution, because that is not the target of the question).

3 0

3 years ago

A scientist, Dr. Sigma, states that a chemical taken internally once a day will prevent the common cold. However, no other scien

pshichka [43]

Answer:

not valid

Explanation:

Expert judgment is a useful validation method to verify the reliability of an investigation that is defined as “an informed opinion of people with experience in the subject, who are recognized by others as qualified experts in it, and who can give information, evidence, judgments and assessments ”

After submitting an instrument for comparison to the consultation and expert opinion, it must meet two quality criteria: validity and reliability. The validity of content is often established based on two situations, one that concerns the design of a test and the other, the validation of an instrument subject to translation and standardization procedures to adapt it to different cultural meanings. It is here that the task of the expert becomes a fundamental task to eliminate irrelevant aspects, incorporate those that are essential and / or modify those that require it.

5 0

4 years ago

Which of the following statements about gamma rays are TRUE? I. Gamma rays have low energy II. Gamma rays are a form of light. I

OverLord2011 [107]

Answer:

the third one

Explanation:

6 0

3 years ago

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