Answer:
2.95 * 10^23 atoms
Explanation:
The number of atoms in a mole is always equal to <u>Avogadro's constant</u>, which is <u>6.02214076×10²³ mol⁻¹</u>.
To find the number of atoms in 0.490 moles of barium, multiply it with <u>Avogadro's constant</u>:
0.490 mol * 6.02214076×10²³ mol⁻¹ ≈ 2.9508 * 10^23
Convert to SigFigs (if necessary):
2.95 * 10^23
Methane gas, which may be present in confined spaces such as a basement, can cause death by asphyxiation.
<h3>
What are the dangers of methane gas in confined space?</h3>
Low amounts are safe for inhalation. A significant amount can replace oxygen in the atmosphere. Reduced oxygen availability can cause symptoms like weariness, emotional instability, fast breathing, and rapid heart rate. Insufficient oxygen can cause nausea, vomiting, collapse, convulsions, coma. The onset of symptoms is accelerated by physical activity. Organs including the heart and brain can suffer long-term damage from a lack of oxygen.
Contact with Skin: Not irritating. The skin might become chilled or frozen when in direct touch with the liquid gas (frostbite). Itching and numbness are signs of mild frostbite. Burning and rigidity are signs of more serious frostbite.
No evidence of carcinogenicity.
learn more about methane gas refer:
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Finding neutrons = Mass number - proton number.
For finding neutrons for phosphorus = 31-15
=16.
25.9 kJ/mol. (3 sig. fig. as in the heat capacity.)
<h3>Explanation</h3>
The process:
.
How many moles of this process?
Relative atomic mass from a modern periodic table:
- K: 39.098;
- N: 14.007;
- O: 15.999.
Molar mass of 
:
.
Number of moles of the process = Number of moles of dissolved:
.
What's the enthalpy change of this process?
for 
. By convention, the enthalpy change 
measures the energy change for each mole of a process.
.
The heat capacity is the least accurate number in these calculation. It comes with three significant figures. As a result, round the final result to three significant figures. However, make sure you keep at least one additional figure to minimize the risk of rounding errors during the calculation.
