Which of the following statements is true for all eukarya?

A. Explain, in terms of particles, why NaCl(s) does not conduct electricity.

yawa3891 [41]

Answer:

Ionic bonds hold charged particles in solid NaCl together, such that they are unable to move or conduct electricity.

Explanation:

Consider an electric current that flows through a conductor: charge moves in a uniform direction from one end of the conductor towards the other.

Thus, there are two conditions for a substance to conduct electricity:

The substance shall contain charged particles, and
These charged particles shall be free to move across the substance.

A conductor of electricity shall meet both requirements.

Now, consider the structure of solid NaCl $\rm NaCl\;(s)$ . NaCl is an ionic compound. It contains an ocean of oppositely charged ions:

Positive $\rm Na^{+}$ ions, and
Negative $\rm Cl^{-}$ ions.

Ions carry charge. Thus, solid NaCl contains charged particles and satisfies the first condition.

Inside solid NaCl $\rm NaCl\;(s)$ , electrostatic attractions ("ionic bonds") between the oppositely charged ions hold these ions in rigid ionic lattices. These ions are unable to move relative to each other. As a result, they cannot flow through the solid to conduct electricity. Under solid state, NaCl is unable to satisfy the second condition.

As a side note, melting NaCl into a liquid breaks the ionic bonds and free the ions from the lattice. Liquid NaCl is a conductor of electricity.

8 0

3 years ago

HELP PLZ ITS A TEST.

tensa zangetsu [6.8K]

Answer:

The answer to your question is below

Explanation:

1 ) Which of the following is a chemical property.

A. Ability to become magnetic this is wrong, it's a physical property

B. Ability to conduct electricity this is wrong, it's a physical property

C. Ability to conduct heat this is wrong, it's a physical property

D. Ability to react with acid This is the right answer

2 ) You heat two substances, A and B. Both substances change color. When cooled, substance B returns to its original color, but substance A does not. What most likely happened?.

A. Physical change occurred in both substances This is wrong, a physial change only happens in substance B

B. A physical change occurred in substance A, and a chemical change occured in substance B. This is wrong, a physical change occurred in substance B and a chemical change occurred in substance A.

C. A chemical change occurred in substance A, and a physical change occurred in substance B. This is the right answer is exactly what happens

D. A chemical change occurred in both substances This answer is wrong.

3 ) how many grams are in 2.5 pound sample? Express your answer in scientific notation with three significant figures. ( 1 pound= 453.592 grams).

Rule of three

1 pound ------------------- 453.592 g

2.5 pounds --------------- x

x = 2.5(453.592)/1

x = 1133.98 g = 1.13 x 10³ g letter D

7 0

3 years ago

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The mole concept is important in chemistry because 1. it allows us to distinguish between elements and compounds. 2. it provides

Rufina [12.5K]

Answer:
<span>The mole concept is important in chemistry because, "</span>Atoms and molecules are very small and the mole concept allows us to count atoms and molecules by weighing macroscopic amounts of material".

Explanation:
To understand this question lets take an example of Hydrogen atom. Let suppose you need to react Hydrogen with Oxygen. You need exactly Two Hydrogen atoms and one Oxygen atom to form one water molecule.
The mass of 1 hydrogen atom is 1.76 × 10⁻²⁴ grams. How will you count the Hydrogen atoms??? How can you measure exactly for 1 Million Hydrogen Atoms???
Answer to these questions and Calculations lies in Mole. It is found that 1 Mole of Hydrogen weights exactly 1.008 gram and contains 6.022 × 10²³ atoms. Now, having this reference in hand you can calculate for any number of Hydrogen atoms.

Result:
So the Mole helps us to zoom a microscopic level to a macroscopic level. :)

6 0

3 years ago

What is the percent composition by mass for hydrogen in water (H2O)?

saw5 [17]

Explanation:

Percentage composition = 2/18 = 11.11%.

5 0

3 years ago

What is the percent by mass of water in Na2SO4 • 10H2O?

bulgar [2K]

We determine the percent by mass of water in the compound by dividing the mass of water by the total mass. The total mass of Na2SO4.10H2O is equal to 322 g. The mass of water is 180 g.

percent by mass of water = (180 / 322)*(100 %) = 55.9%

5 0

3 years ago

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