The information below describes a redox reaction.

Which of the following must be the same for two isotopes of an element? A. The number of neutrons B. The atomic number C. The ma

ASHA 777 [7]

B. The atomic number. This is because the atomic number is the same as the number of protons an element has, and the number of protons defines an element.

8 0

2 years ago

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A student has a balloon that looks shiny like a metal and wants to perform an experiment to determine if it contains any metal.

zheka24 [161]

Answer:

Charge the balloon, hold it near an electroscope, and determine if the electroscope leaves move.

Explanation:

The gold leaf electroscope is an instrument used to detect if a body is charged. It has two gold leafs suspended from a brass stem in a vacuumed glass jar and connected to a metal cap(Toppr).

When the test body is allowed to touch the metal cap, a change in the size of the leaves shows whether the body is charged or not.

Since we are suspecting the balloon to be made up of a metal; metals can be charged. We can test if there is really a charge on the balloon by bringing it near an electroscope to see if the electroscope moves.

3 0

2 years ago

Solid NaI is slowly added to a solution that is 0.0079 M Cu+ and 0.0087 M Ag+.Which compound will begin to precipitate first?NaI

NeTakaya

Answer :

AgI should precipitate first.

The concentration of $Ag^+$ when CuI just begins to precipitate is, $6.64\times 10^{-7}M$

Percent of $Ag^+$ remains is, 0.0076 %

Explanation :

$K_{sp}$ for CuI is $1\times 10^{-12}$

$K_{sp}$ for AgI is $8.3\times 10^{-17}$

As we know that these two salts would both dissociate in the same way. So, we can say that as the Ksp value of AgI has a smaller than CuI then AgI should precipitate first.

Now we have to calculate the concentration of iodide ion.

The solubility equilibrium reaction will be:

$CuI\rightleftharpoons Cu^++I^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Cu^+][I^-]$

$1\times 10^{-12}=0.0079\times [I^-]$

$[I^-]=1.25\times 10^{-10}M$

Now we have to calculate the concentration of silver ion.

The solubility equilibrium reaction will be:

$AgI\rightleftharpoons Ag^++I^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ag^+][I^-]$

$8.3\times 10^{-17}=[Ag^+]\times 1.25\times 10^{-10}M$

$[Ag^+]=6.64\times 10^{-7}M$

Now we have to calculate the percent of $Ag^+$ remains in solution at this point.

Percent of $Ag^+$ remains = $\frac{6.64\times 10^{-7}}{0.0087}\times 100$

Percent of $Ag^+$ remains = 0.0076 %

8 0

3 years ago

Which answer below correctly identifies the type of change and the explanation when magnesium comes into contact with hydrochlor

Oliga [24]

Answer:

A chemical change because a temperature change occurred, the solid disappeared and a gas was produces

Explanation:

Magnesium reacts with hydrochloric acid releasing energy, and leading to the formation of magnesium chloride and hydrogen gas. This is represented by the equation below:

Mg₍s₎ + 2HCl₍aq)⇒ MgCl₂₍aq₎ + H₂₍g₎

5 0

3 years ago

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Radiation with a wavelength of 4.2nm

viva [34]

The answer is X Ray

Hope it helps

6 0

3 years ago