What is the meaning of polyatomic

Suppose you have 100 grams of radioactive plutonium-239 with a half-life of 24,000 years. how many grams of plutonium-239 will r

Alexandra [31]

To solve this problem, let us first calculate for the rate constant k using the half life formula:

t1/2 = ln 2 / k

where t1/2 = half life period = 24,000 years, therefore k is:

k = ln 2 / 24,000

k = 2.89 x 10^-5 / yr

Now we use the rate equation:

A = Ao e^(-k t)

where,

A = mass of Plutonium-239 after number of years

Ao = initial mass of Plutonium-239

t = number of years

A. t = 12,000 years, find A

A = 100g e^(- 2.89 x 10^-5 * 12,000)

A = 70.7 g

B. t = 24,000 years, find A

A = 100g e^(- 2.89 x 10^-5 * 24,000)

A = 50 g

C. t = 96,000 years, find A

A = 100g e^(- 2.89 x 10^-5 * 96,000)

5 0

3 years ago

Select the correct answer.

hichkok12 [17]

Answer:

A. The model could not explain how alpha particles could be deflected at large angles.

Explanation:

The plum pudding model of the atom was proposed by J. J Thomson. He suggested that that an atom is made up of dense particles of electrons surrounded by positive charges.

From the Gold foil experiment carried out by Ernest Rutherford, he noticed that the bulk of the alpha particles targeted at the foil passed through and a little fraction was heavily deflected back.

Rutherford then presented his nuclear model from here. He suggested a massive, dense and tiny nucleus where the protons and neutrons are located. The space outside the mass is dominated by orbiting electrons.

6 0

3 years ago

I need this answer quick please show work

Ainat [17]

Answer:

The answer to your question is 25.2 g of acetic acid.

Explanation:

Data

[Acetic acid] = 0.839 M

Volume = 0.5 L

Molecular weight = 60.05 g/mol

Process

1.- Calculate the number of moles of acetic acid

Molarity = moles / volume

-Solve for moles

moles = Molarity x volume

-Substitution

moles = (0.839)(0.5)

-Result

moles = 0.4195

2.- Calculate the mass of acetic acid using proportions and cross multiplications

60.05 g ----------------------- 1 mol

x ----------------------- 0.4195 moles

x = (0.4195 x 60.05) / 1

x = 25.19 g

3.- Conclusion

25.2 g are needed to prepare 0.500 L of Acetic acid 0.839M

4 0

3 years ago

A 0.533 g sample of a carbonate salt is added to a flask. The only thing you know is that per formula unit, there is only one ca

dimulka [17.4K]

Answer:

$\mathbf{CrCO_3}$

Explanation:

The total mole of $H_2SO_4$ added = 15 × 1 × 10⁻³

= 15 × 10⁻³ mole

= 15 mmoles

the number of moles of NaOH added in order to neutralize the excess acid = 0.5905 × 29.393 = 17.36 mmoles

the equation for the reaction is:

2NaOH + $H_2SO_4$ --------> $Na_2SO_4 +2H_2O$

i.e

2 moles of NaOH react with $H_2SO_4$

1 moles of NaOH will react with 1/2 $H_2SO_4$

17.36 mmoles of NaOH = 1/2 × 17.36 mmoles of $H_2SO_4$

= 8.68 mmoles

Number of moles of $H_2SO_4$ that react with MCO₃ = Total moles of $H_2SO_4$ added - moles of $H_2SO_4$ reacted with NaOH

= (15 - 8.68) mmoles

= 6.32 mmoles

$H_2SO_4$ + $MCO_3$ ------> $M_2SO_4$ + $H_2O$ + $CO_2$

1 mole of $H_2SO_4$ react with 1 mole of $MCO_3$

6.32 mmoles of $H_2SO_4$ = 6.32 mmoles of $MCO_3$

number of moles of $MCO_3$ = 6.32 10⁻³ moles

mass of $MCO_3$ (carbonate salt) = 0.533 g

molar mass of $MCO_3$ = (M+60)g/mol

We all know that ;

number of moles = mass/molar mass

Then:

6.32 10⁻³ = 0.533 / (M+60)

(M+60) = 0.533/ 6.32 10⁻³

M + 60 = 84.34

M = 84.34 - 60

M = 24.34

Thus the element with the atomic mass of 24.34 is Chromium

The chemical formula for the compound is : $\mathbf{CrCO_3}$

6 0

3 years ago

Help Ill give you the brainiest answer thing please just give me the right answer

yaroslaw [1]

Answer:

the 3rd one

Explanation:

5 0

3 years ago

Read 2 more answers