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3 years ago

Which missing item would complete this beta decay reaction?

Chemistry

1 answer:

Jet001 [13]3 years ago

8 0

We know that the mass number (top number) must be 33 because the electron that is emitted has no mass. The atomic number (bottom number) must be 15, because it is one less than 16 and the electron has a negative charge. Therefore, the first box is the answer.

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Read the information about the halogen family.

Elodia [21]

Answer:

See explanation

Explanation:

Chlorine is a member of the halogen family known as a toxic yellowish green gas. Inhalation of chlorine for a prolonged period of time leads to pulmonary edema. If a person comes in contact with compressed liquid chlorine the person may experience frostbite of the skin and eyes.

However chlorine is very useful in water disinfection and is preferred in water treatment because it provides residual disinfection of the treated water.

Chlorine gas may be dissolved in NaOH to form oxochlorate I which is used as a bleach in cleaning.

7 0

3 years ago

Why do copper ions go to the negative electrode

Snowcat [4.5K]

Its because the copper ions have a positive charge, therefore, they are attracted to a negative electrode.

8 0

3 years ago

Lesson Four: Significant Figures in Calculations

MArishka [77]

Answer:

a) significant figures b) decimal places

Multiplying/dividing ex: 1.33 * 4.4932 = 5.98 because the first component only has three sig figs while the second has five.

Adding/subtracting ex: 12.13 + 53.5763 = 65.71 we ignore the whole numbers and focus only on the decimal places. The first component only has two while the second has four. Hope this helps!

5 0

3 years ago

An aqueous solution of sodium fluoride is slowly added to a water sample that contains barium ion (2.75×10-2M ) and calcium ion

Alona [7]

Answer : The remaining concentration of the first ion to precipitate when the second ion begins to precipitate is, $1.07\times 10^{-6}M$

Explanation :

The dissociation of barium fluoride is written as:

$BaF_2\rightleftharpoons Ba^{2+}+2F^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ba^{2+}][F^-]^2$

As we know that at room temperature $25^oC$ the $K_{sp}$ of barium fluoride is, $1\times 10^{-6}$ .

Now put all the given values in this expression, we get:

$1\times 10^{-6}=(2.75\times 10^{-2})\times [F^-]^2$

$[F^-]=6.03\times 10^{-3}M=0.00603M$

The barium fluoride precipitate when fluoride ion is equal to 0.00603 M.

The dissociation of calcium fluoride is written as:

$CaF_2\rightleftharpoons Ca^{2+}+2F^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ca^{2+}][F^-]^2$

As we know that at room temperature $25^oC$ the $K_{sp}$ of calcium fluoride is, $3.90\times 10^{-11}$ .

Now put all the given values in this expression, we get:

$3.90\times 10^{-11}=(6.70\times 10^{-2})\times [F^-]^2$

$[F^-]=2.41\times 10^{-5}M=0.0000241M$

The calcium fluoride precipitate when fluoride ion is equal to 0.0000241 M.

Since, the fluoride ion concentration in calcium fluoride is less then the fluoride ion concentration in barium fluoride. That means, calcium fluoride will precipitate first.

Thus, the concentration $Ca^{2+}$ ion remaining at $F^-$ concentration (0.00603 M) is calculated as: