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3 years ago

The symbol for a radioactive nuclide is 210/84 Po. which statement is correct

Chemistry

2 answers:

Alika [10]3 years ago

8 0

Answer:

The number of neutrons present in the nucleus of each atom is 126.

Explanation:

Rudik [331]3 years ago

6 0

Answer is: The number of neutrons present in the nucleus of each atom is 126.

Polonium (Po) has atomic number 84. Atomic number (Z) is the number of protons, which is characteristic of a chemical element.

Z = p⁺ = 84.

A = p⁺ + n°; mass number is the total number of protons and neutrons in a nucleus.

A = 210.

n° = 210 - 84.

n° = 126; number of neutrons.

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GaryK [48]

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3 years ago

Read 2 more answers

When 2.00 g of methane are burned in a bomb calorimeter, the change in temperature is 3.08°C. The heat capacity of the calorimet

melisa1 [442]

Answer:

The approximate molar enthalpy of combustion of this substance is -66 kJ/mole.

Explanation:

First we have to calculate the heat gained by the calorimeter.

$q=c\times \Delta T$

where,

q = Heat gained = ?

c = Specific heat = $2.68 kJ/^oC$

ΔT = The change in temperature = 3.08°C

Now put all the given values in the above formula, we get:

$q=2.68 kJ/^oC\times 3.08^oC$

$q=8.2544 kJ$

Now we have to calculate molar enthalpy of combustion of this substance :

$\Delta H_{comb}=-\frac{q}{n}$

where,

$\Delta H_{comb}$ = enthalpy change = ?

q = heat gained = 8.2544kJ

n = number of moles methane = $\frac{\text{Mass of methane}}{\text{Molar mass of methane }}=\frac{2.00 g}{16.042 g/mol}=0.1247 mole$

$\Delta H_{comb}=-\frac{8.2544 kJ}{0.1247 mole}=-66.21 kJ/mole\approx -66 kJ/mole$

Therefore, the approximate molar enthalpy of combustion of this substance is -66 kJ/mole.

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3 years ago

Explain why it is important that there be no gaps around the edges of the filter paper during a vacuum filtration

lesantik [10]

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3 years ago

How much of a 24-gram sample of Radium-226 will remain unchanged at the end of three half-life periods?

shutvik [7]

Answer:

The right answer is "3 g".

Explanation:

Given:

Initial mass substance,

$M_0=24 \ g$